Agricultural technology knowledge retrieval service method and system based on a knowledge graph

Abstract

The application discloses a kind of based on knowledge graph's agricultural technology knowledge retrieval service method and system, comprising the following steps: load pre-built agricultural technology knowledge graph and CompGCN combination propagation structure, determine retrieval entrance and temporary relationship state;Problem is disassembled into crop scene anchor, symptom fact anchor, respectively access corresponding relationship edge;Isolated invalid aggregation by combination test broadcast;Double-anchor closed screening pest node;Along prevention and cure measure, agricultural materials, agricultural materials forbidden limit relationship advance;Reverse turn back check agricultural materials adaptability;Lock invalid path, release effective evidence path, generate agricultural technology knowledge retrieval result.The application relates to the field of agricultural informatization technology, realizes accurate retrieval of agricultural technology knowledge, improves result reliability and service efficiency.

Description

Technical Field

[0001] This invention relates to the field of agricultural information technology, and in particular to a method and system for agricultural technology knowledge retrieval services based on knowledge graphs. Background Technology

[0002] Current agricultural technology knowledge retrieval methods largely rely on keyword matching or simple semantic retrieval, directly matching crop names or pest / disease names in a knowledge base to return results. Some solutions introduce knowledge graph structures, modeling relationships between crops, pests / diseases, control measures, and agricultural input information, and using graph computing methods to achieve node-related queries, thereby improving retrieval coverage and semantic relevance. Building on this, some methods combine graph neural network models to propagate node relationships, enhancing the ability to express multi-hop related information and thus improving the fragmentation problem of traditional retrieval results.

[0003] In practical applications, existing technologies still have shortcomings in complex agricultural technology scenarios. Agricultural technology problems often simultaneously include crop environmental information and pest and disease symptom information. Single-path propagation can easily lead to semantic shifts, resulting in mismatches of pests and diseases or inconsistent control recommendations. Knowledge graph propagation typically employs a unified neighborhood diffusion mechanism, failing to differentiate information from different semantic sources. This leads to excessive fusion of scenario and symptom information during propagation, reducing the relevance of search results. When dealing with the association between agricultural input restrictions and control measures, existing methods lack a backtracking verification mechanism for restrictions, easily resulting in recommendations that do not conform to agricultural input usage standards. Furthermore, there is a lack of effective means to suppress invalid paths during propagation, allowing noisy relationships to continue spreading during multi-hop propagation, affecting the stability of the final search results.

[0004] Therefore, how to provide a method and system for agricultural technology knowledge retrieval based on knowledge graphs is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] One objective of this invention is to propose a knowledge graph-based agricultural technology knowledge retrieval service method and system. This invention utilizes the CompGCN combined propagation structure to construct a combined trial sowing, double-anchor closure, reverse return of agricultural input prohibition and restriction relationships, and closed propagation path write-back process, realizing scenario-based retrieval of agricultural technology problems. It has the advantages of fewer mismatches, high security of agricultural input recommendations, and strong interpretability of retrieval results.

[0006] A method for agricultural technology knowledge retrieval service based on knowledge graphs according to an embodiment of the present invention includes the following steps: The pre-built agricultural technology knowledge graph is loaded into the CompGCN combinatorial propagation structure, the entry point for this round of retrieval and propagation is locked, and the temporary relation state for this round is initialized. The agricultural technology retrieval problem is broken down into crop scenario anchors and symptom fact anchors. Crop scenario anchors are connected to scenario adaptation relationship edges, and symptom fact anchors are connected to fact pointing relationship edges. Perform a combined trial broadcast on the relation edges adjacent to the crop scene anchor and the symptom fact anchor. Write the trial broadcast propagation path into the relation trial broadcast slot and close the entrance to the neighborhood aggregation of the relation trial broadcast slot. The trial sowing propagation path is advanced from the relationship trial sowing slot to the pest and disease node. When the pest and disease node simultaneously receives the crop scene anchor propagation path and the symptom fact anchor propagation path, double anchor closure is performed. When the pest and disease node only receives a single propagation path, the single propagation path is marked as a closed propagation path. Taking the double-anchored closed pest and disease node as the entry point, the CompGCN combined propagation structure advances along the control measures node and agricultural input node to the agricultural input restriction relationship; Perform a reverse backtracking along the agricultural input restriction relationship towards the crop scene anchor. If the reverse backtracking hits the crop scene anchor but does not trigger the restriction state recorded in the agricultural input restriction relationship, it is marked as a release propagation path. If the reverse backtracking does not hit the crop scene anchor, it is marked as a locked propagation path. If the reverse backtracking triggers the restriction state recorded in the agricultural input restriction relationship, it is marked as a locked propagation path. The closed propagation path is written back to the current temporary relationship state, the released propagation path is written to the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot.

[0007] Optionally, the initialization of the current round's temporary relationship state specifically includes: Establish positional entries for this round of retrieval and dissemination based on the relationship types in the pre-built agricultural technology knowledge graph; Set the current relationship placeholder as the current temporary relationship state, set the current temporary relationship state to the non-write-back state, and clear the relationship trial slot write mark, the locked propagation path write mark, and the released propagation path write mark; Before the closed propagation path is written back, the temporary relationship status in this round only records the relationship edge markers passed through by the trial propagation path in the relationship trial sowing slot, and the relationship edges in the pre-built agricultural technology knowledge graph are not updated; After the locking propagation path is written back, the relation edges traversed by the locking propagation path are marked as locking relation edges in this round. When subsequent combination trial broadcasts in this round traverse the locking relation edges in this round, the corresponding trial broadcast propagation path is marked as a locking propagation path.

[0008] Optionally, the agricultural technology retrieval question is broken down into crop scenario anchors and symptom fact anchors, specifically including: Based on the scene adaptation relationship edge and the fact pointing relationship edge within the current retrieval and dissemination entry point, the agricultural technology retrieval question is divided into two anchors. Search terms that match the scene adaptation relationship edge are written into the crop scene anchor, and search terms that match the fact pointing relationship edge are written into the symptom fact anchor. The crop scene anchor is connected to the current round of retrieval propagation entry along the scene adaptation relationship edge that is hit; the symptom fact anchor is connected to the current round of retrieval propagation entry along the fact pointing relationship edge that is hit. Search terms that do not match the scene adaptation relationship edge are not written to the crop scene anchor, and search terms that do not match the fact pointing relationship edge are not written to the symptom fact anchor.

[0009] Optionally, the combined trial planting of the adjacent relationship edges between the crop scene anchor and the symptom fact anchor specifically includes: The crop scene anchor forms a scene-side trial broadcast propagation path along the hit scene adaptation relationship edge, and the symptom fact anchor forms a fact-side trial broadcast propagation path along the hit fact pointing relationship edge; Write the scene-side test broadcast propagation path and the fact-side test broadcast propagation path into the relationship test broadcast slot, and add an unaggregated mark to the scene-side test broadcast propagation path and the fact-side test broadcast propagation path; The relationship test broadcast slot keeps the entrance to the neighborhood aggregation closed, and the scene-side test broadcast propagation path with the unaggregated marker and the fact-side test broadcast propagation path only advance to the pest and disease node; After the double anchor closure is completed, remove the unaggregated markers from the scenario-side test broadcast propagation path and the fact-side test broadcast propagation path that have completed the double anchor closure. Test broadcast propagation paths whose unaggregated markers have not been removed will not enter the prevention and control measures node.

[0010] Optionally, the double-anchor closure specifically includes: The scene-side test broadcast propagation path is written into the scene-side arrival position of the pest and disease node, and the fact-side test broadcast propagation path is written into the fact-side arrival position of the pest and disease node. When there are write records for both the scene-side arrival location and the fact-side arrival location within the same pest and disease node, a double-anchor closure mark is generated after the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are matched. Pest and disease nodes with double-anchor closed tags are retained as double-anchor closed pest and disease nodes, and the unaggregated tags of the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are removed. When only the scene-side arrival position has a write record, the scene-side test broadcast propagation path is marked as a latched propagation path; when only the fact-side arrival position has a write record, the fact-side test broadcast propagation path is marked as a latched propagation path.

[0011] Optionally, the CompGCN combined propagation structure, using the double-anchored closed pest and disease node as the entry point, advances along the control measure node and agricultural input node to the agricultural input restriction relationship, specifically including: Pest and disease nodes marked with double anchor closures have open control measures; pest and disease nodes without double anchor closures do not have open control measures. The scenario-side test broadcast propagation path with double-anchor closure markers and the fact-side test broadcast propagation path are merged into the double-anchor closure propagation path; The double-anchor closed propagation path enters the prevention and control measure node along the relationship between prevention and control measures, and enters the agricultural input node along the relationship between the application of agricultural inputs. The dual-anchor closed propagation path advances from the agricultural input node to the agricultural input prohibition and restriction relationship. When the prevention and control measure relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path. When the agricultural input applicability relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path.

[0012] Optionally, the reverse backtracking along the agricultural input restriction and prohibition relationship to the crop scenario anchor specifically includes: When the double-anchor closed propagation path reaches the agricultural input restriction / prohibition relationship, it turns into a reverse turnback; The reverse turnback follows the agricultural input restriction and prohibition relationship back to the crop scene anchor; When the reverse return hits the crop scene anchor and does not trigger the restriction state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as the release propagation path; When the reverse return fails to hit the crop scene anchor, the double-anchor closed propagation path is marked as a locked propagation path; When the reverse return triggers the restricted state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as a locked propagation path.

[0013] Optionally, the locking propagation path is written back to the current round's temporary relation state, specifically including: Mark the edges along the locking propagation path as the locking relationship edges in this round; A blocking source marker is generated based on the location where the blocking propagation path is formed. The blocking source marker is one of the following: single-path arrival blocking marker, relationship missing blocking marker, backtracking miss blocking marker, and restriction state triggered blocking marker. Write the locking source marker and the propagation direction of the locking propagation path into the locking relationship edge in this round; When subsequent combination test broadcasts pass through the locking relationship edge of this round, the test broadcast propagation path whose propagation direction is consistent with the propagation direction recorded in the locking relationship edge of this round is marked as the locking propagation path.

[0014] Optionally, the release propagation path is written into the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot, specifically including: The crop scene anchors, symptom fact anchors, double-anchor closed pest and disease nodes, prevention and control measure nodes, agricultural input nodes, and agricultural input restriction and prohibition relationships along the transmission path are written into the evidence path slot in the order of transmission. The double-anchor closure marker, the reverse return record of the crop scene anchor, and the verification record of the restriction status that does not trigger the agricultural input restriction relationship are written into the evidence path slot; The evidence path slots form an evidence chain according to the propagation order of the release propagation path; In the chain of evidence, the double-anchored closed pest and disease node is used as the search hit node, the prevention and control measure node is used as the search measure node, the agricultural input node is used as the search agricultural input node, and the agricultural input prohibition and restriction relationship is used as the search restriction relationship. Agricultural technology knowledge retrieval results are generated based on search hit nodes, search measure nodes, search agricultural input nodes, and search restriction relationships.

[0015] An agricultural technology knowledge retrieval service system based on a knowledge graph according to an embodiment of the present invention includes the following modules: The graph loading module is used to load the pre-built agricultural technology knowledge graph into the CompGCN combinatorial propagation structure, lock the entry point of the current round of retrieval and propagation, and initialize the temporary relationship state of the current round. The dual-anchor access module is used to split agricultural technology retrieval questions into crop scenario anchors and symptom fact anchors, and respectively access scenario adaptation relationship edges and fact pointing relationship edges; The combined trial broadcast module is used to perform combined trial broadcasts on the relation edges adjacent to the crop scene anchor and the symptom fact anchor, write the trial broadcast propagation path into the relation trial broadcast slot, and close the entrance of the relation trial broadcast slot to the neighborhood aggregation. The trial sowing advancement module is used to advance the trial sowing propagation path from the relationship trial sowing slot to the disease and pest node, execute double anchor closure, and mark the closed propagation path; The measures advancement module is used to advance from the pest and disease node with double-anchor closure as the entry point, along the prevention and control measures node and agricultural input node to the agricultural input restriction relationship; The reverse turnaround module is used to perform a reverse turnaround along the agricultural input restriction relationship to the crop scene anchor, marking the release propagation path and the locking propagation path; The write-back output module is used to write back the locking propagation path to the current round's temporary relationship state, write the release propagation path into the evidence path slot, and generate agricultural technology knowledge retrieval results.

[0016] The beneficial effects of this invention are: (1) The present invention temporarily stores the trial broadcast propagation path in the neighborhood aggregation through the relationship trial broadcast slot. Before the double anchor closure is completed, the entrance of the relationship trial broadcast slot to the neighborhood aggregation is closed, so that the crop scene anchor propagation path and the symptom fact anchor propagation path are decoupled and verified before entering the aggregation, avoiding the direct triggering of pest and disease recommendations by a single symptom hit or a single crop association, and reducing false searches caused by cross crops and cross symptoms.

[0017] (2) This invention uses the double-anchored closed pest and disease node as the entry point for the spread of prevention and control measures. Only the scenario-side trial sowing propagation path and the fact-side trial sowing propagation path are allowed to continue to advance to the prevention and control measure node and agricultural input node after they are connected at the same pest and disease node. This makes the agricultural technology knowledge retrieval results subject to both crop scenario and symptom facts, thereby improving the consistency between pest and disease judgment, prevention and control measure matching, and agricultural input recommendation.

[0018] (3) This invention performs a reverse backtracking to the crop scene anchor through the agricultural input restriction relationship, marks the propagation path that triggers the restriction state or fails to hit the crop scene anchor as a locked propagation path, and then writes the locked propagation path back to the temporary relationship state of this round, so that the erroneous path is suppressed in the subsequent combination trial sowing in this round, avoiding the continued spread of incompatible agricultural inputs, prevention and control measures and restriction conditions, and improving the safety, interpretability and stability of agricultural technology retrieval results. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a knowledge graph-based agricultural technology knowledge retrieval service method proposed in this invention; Figure 2 This is a flowchart of the double-anchor segmentation and relational trial seeding trench isolation process proposed in this invention; Figure 3 This is a flowchart of the double-anchor closed propagation and reverse return process for agricultural input restrictions proposed in this invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0021] refer to Figures 1-3 A knowledge graph-based method for retrieving agricultural technical knowledge includes the following steps: The pre-built agricultural technology knowledge graph is loaded into the CompGCN combinatorial propagation structure, the entry point for this round of retrieval and propagation is locked, and the temporary relation state for this round is initialized. In this invention, the pre-built agricultural technology knowledge graph is pre-organized agricultural technology graph data, including agricultural technology entity nodes, relationship edges, relationship types, and propagation directions. Agricultural technology entity nodes include crop nodes, symptom nodes, pest and disease nodes, control measure nodes, and agricultural input nodes. Relationship edges include scenario-adaptation relationship edges, fact-pointing relationship edges, control measure relationships, agricultural input applicability relationships, and agricultural input prohibition / restriction relationships. Agricultural input prohibition / restriction relationships record restriction states, including unrestricted state, prohibited state, restricted use state, and safety interval state. The unrestricted state is when no usage restrictions are recorded in the agricultural input prohibition / restriction relationship. The prohibited state is when the corresponding agricultural input is prohibited from use. The restricted use state is when the corresponding agricultural input has limited usage conditions. The safety interval state is when the corresponding agricultural input has a safety interval restriction. The CompGCN combined propagation structure is a combined multi-relation graph convolutional structure used to perform combined propagation on the entity vectors corresponding to agricultural technology entity nodes and the relation vectors corresponding to relation edges. When loading a pre-built agricultural technology knowledge graph, agricultural technology entity nodes are written into the entity vector table, relation edges are written into the relation vector table, relation types are written into the relation type index, and the propagation direction is written into the relation vector table along with the corresponding relation edge. The entry point for this round of retrieval propagation is the access position of the crop scene anchor and symptom fact anchor in the current agricultural technology retrieval; when locking the entry point for this round of retrieval propagation, the scene-adaptive relation edge entry point and the fact-pointing relation edge entry point are selected from the relation type index; the temporary relation status in this round is a temporary status table that records trial sowing, locking, and release in the current agricultural technology retrieval. During initialization, the relationship trial sowing slot write flag, the locking propagation path write flag, and the release propagation path write flag are all set to 0; The agricultural technology retrieval problem is broken down into crop scenario anchors and symptom fact anchors. Crop scenario anchors are connected to scenario adaptation relationship edges, and symptom fact anchors are connected to fact pointing relationship edges. In this invention, the agricultural technology retrieval question is the query text input by the user; the retrieval terms are word fragments obtained by segmenting the agricultural technology retrieval question according to the node names and relation type names in the pre-built agricultural technology knowledge graph; the crop scene anchor is a temporary entry point carrying scene-type retrieval terms, and the symptom fact anchor is a temporary entry point carrying fact-type retrieval terms; A hit occurs when the search term matches any one of the following names: the starting node name, the ending node name, or the relation type name. Search terms that match the scene-adapted relation edge are written to the crop scene anchor, and search terms that match the fact-pointing relation edge are written to the symptom fact anchor. The entity vector corresponding to the crop scene anchor is written from the entity vector of the agricultural technology entity node corresponding to the search term that matches the scene-adapted relation edge, and the entity vector corresponding to the symptom fact anchor is written from the entity vector of the agricultural technology entity node corresponding to the search term that matches the fact-pointing relation edge. When several agricultural technology entity nodes are hit, the value of the k-th dimension entity vector is taken as the arithmetic mean of the values ​​of the k-th dimension entity vectors of the several hit agricultural technology entity nodes, where k is the vector dimension index. Perform a combined trial broadcast on the relation edges adjacent to the crop scene anchor and the symptom fact anchor. Write the trial broadcast propagation path into the relation trial broadcast slot and close the entrance to the neighborhood aggregation of the relation trial broadcast slot. In this invention, adjacent relational edges are relational edges that are directly connected between crop scene anchors and symptom fact anchors in the pre-built agricultural technology knowledge graph; the relational edges adjacent to crop scene anchors are scene adaptation relational edges, and the relational edges adjacent to symptom fact anchors are fact pointing relational edges. The combined trial broadcast is a temporary propagation performed by the CompGCN combined propagation structure without updating node representations. During the combined trial broadcast, the entity vectors corresponding to crop scene anchors and symptom fact anchors are read from the entity vector table, and the relation vectors corresponding to scene adaptation relation edges and fact pointing relation edges are read from the relation vector table. Entity vectors and relation vectors within the same path are multiplied by the same dimension to obtain the combined propagation vector. Multiplication by the same dimension is the multiplication of the k-th dimension entity vector value and the k-th dimension relation vector value, where k is the vector dimension index. The trial propagation path is a temporary path record obtained from combined trial propagation. Each trial propagation path records the combined propagation vector, starting anchor point, passed relation edges, and propagation direction. The relation trial propagation slot is the temporary path storage area in this round of retrieval. When a trial propagation path is written into a relation trial propagation slot, a non-aggregated flag is added. A value of 1 indicates that it has not entered the neighborhood aggregation, and a value of 0 indicates that it is allowed to enter the neighborhood aggregation. When the entrance from the relation trial propagation slot to the neighborhood aggregation is closed, the neighborhood aggregation entrance flag is set to 0. When the neighborhood aggregation entrance flag is 0, the trial propagation path in the relation trial propagation slot only advances to the pest and disease node. When the neighborhood aggregation entrance flag is 1, the trial propagation path in the relation trial propagation slot is allowed to enter the neighborhood aggregation. Neighborhood aggregation is the calculation process in the CompGCN combined propagation structure that merges the trial propagation paths corresponding to adjacent relation edges into the target node representation. The trial sowing propagation path is advanced from the relationship trial sowing slot to the pest and disease node. When the pest and disease node simultaneously receives the crop scene anchor propagation path and the symptom fact anchor propagation path, double anchor closure is performed. When the pest and disease node only receives a single propagation path, the single propagation path is marked as a closed propagation path. In this invention, the disease and pest node is a node representing disease and pest objects in a pre-built agricultural technology knowledge graph; the advancement of the trial sowing propagation path is to send the trial sowing propagation path with unaggregated markers in the relationship trial sowing slot into the disease and pest node according to the propagation direction recorded in the trial sowing propagation path. The crop scene anchor propagation path is the trial propagation path formed from the crop scene anchor, and the symptom fact anchor propagation path is the trial propagation path formed from the symptom fact anchor; synchronous reception means that the same pest node receives both the crop scene anchor propagation path and the symptom fact anchor propagation path in this round of retrieval; double anchor closure means that the crop scene anchor propagation path and the symptom fact anchor propagation path received by the same pest node are combined to generate a double anchor closure marker. A single-path propagation path is a trial propagation path that receives only one of the following from the same pest / disease node: a crop scene anchor propagation path or a symptom fact anchor propagation path. A locked propagation path is a propagation path whose subsequent propagation is blocked in this round of retrieval. When a single-path propagation path is marked as a locked propagation path, it is prohibited from advancing into the control measures node. When a single-path propagation path is marked as a locked propagation path, the locked mark of the single-path propagation path is set to 1. When the locked mark value is 1, the single-path propagation path is prohibited from advancing into the control measures node. When the locked mark value is 0, the propagation path is not locked. Taking the double-anchored closed pest and disease node as the entry point, the CompGCN combined propagation structure advances along the control measures node and agricultural input node to the agricultural input restriction relationship; In this invention, the pest and disease node with double-anchor closure is a pest and disease node marked with a double-anchor closure value of 1; the control measure node is a node in the pre-built agricultural technology knowledge graph that records control operations, and is connected to the pest and disease node through the control measure relationship; the agricultural input node is a node in the pre-built agricultural technology knowledge graph that records pesticides, fertilizers, and biological agents, and is connected to the control measure node through the agricultural input application relationship; the agricultural input restriction relationship is a relationship edge in the pre-built agricultural technology knowledge graph that records restrictions on the use of agricultural inputs, and the agricultural input restriction relationship connects the agricultural input node and records the corresponding restriction status; the progression to the agricultural input restriction relationship is a double-anchor closure propagation path that enters the control measure node along the control measure relationship, enters the agricultural input node along the agricultural input application relationship, and then enters the agricultural input restriction relationship from the agricultural input node; the double-anchor closure propagation path records the propagation order of crop scene anchor, pest and disease node, control measure node, agricultural input node, and agricultural input restriction relationship; Perform a reverse backtracking along the agricultural input restriction relationship towards the crop scene anchor. If the reverse backtracking hits the crop scene anchor but does not trigger the restriction state recorded in the agricultural input restriction relationship, it is marked as a release propagation path. If the reverse backtracking does not hit the crop scene anchor, it is marked as a locked propagation path. If the reverse backtracking triggers the restriction state recorded in the agricultural input restriction relationship, it is marked as a locked propagation path. In this invention, the reverse return is a verification operation that returns to the crop scene anchor in reverse according to the recorded propagation order of the double-anchor closed propagation path after the double-anchor closed propagation path reaches the agricultural input restriction relationship; hitting the crop scene anchor means that the node reached when the reverse return stops is consistent with the crop scene anchor; missing the crop scene anchor means that the node reached when the reverse return stops is inconsistent with the crop scene anchor. The restricted status recorded when the agricultural input restriction relationship is triggered is one of the following states: prohibited, restricted, or safe interval among the agricultural input restriction relationships passed through in the reverse turn; the restricted status recorded when the agricultural input restriction relationship is not triggered is only unrestricted among the agricultural input restriction relationships passed through in the reverse turn. The release propagation path is a double-anchor closed propagation path that allows writing to the evidence path slot. When the reverse return hits the crop scene anchor and does not trigger the restriction state recorded in the agricultural input prohibition and restriction relationship, the release flag of the double-anchor closed propagation path is set to 1. When the release flag is 1, the double-anchor closed propagation path is allowed to be written to the evidence path slot. When the release flag is 0, the double-anchor closed propagation path is not released. When the reverse return does not hit the crop scene anchor or triggers the restriction state recorded in the agricultural input prohibition and restriction relationship, the locking flag of the double-anchor closed propagation path is set to 1, and the double-anchor closed propagation path is marked as a locked propagation path. When the double-anchor closed propagation path is marked as a locked propagation path, writing to the evidence path slot is prohibited. The closed propagation path is written back to the current temporary relationship state, the released propagation path is written to the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot.

[0022] In this invention, write-back is the operation of writing the locked record of the locked propagation path in the current round of retrieval into the temporary relation state of the current round; when the locked propagation path is written back to the temporary relation state of the current round, the relation edges and propagation direction traversed by the locked propagation path are recorded, and the relation edges in the pre-built agricultural technology knowledge graph are not rewritten; The evidence path slot is a temporary record area for storing the release and propagation path during this round of retrieval. When the release and propagation path is written into the evidence path slot, the crop scenario anchor, symptom fact anchor, double-anchor closed pest and disease node, prevention and control measure node, agricultural input node, and agricultural input restriction and prohibition relationship are recorded in the propagation order of the release and propagation path. When generating agricultural technology knowledge retrieval results, the double-anchor closed pest and disease node, prevention and control measure node, agricultural input node, and agricultural input restriction and prohibition relationship are extracted from the evidence path slot to form agricultural technology knowledge retrieval results corresponding to the agricultural technology retrieval question in this round.

[0023] In this embodiment, initializing the temporary relationship state for this round specifically includes: Establish positional entries for this round of retrieval and dissemination based on the relationship types in the pre-built agricultural technology knowledge graph; In this invention, the current relationship occupancy is a temporary record position established according to the relationship types in the pre-built agricultural technology knowledge graph, and each relationship type corresponds to one current relationship occupancy. Set the current relationship placeholder as the current temporary relationship state, set the current temporary relationship state to the non-write-back state, and clear the relationship trial slot write mark, the locked propagation path write mark, and the released propagation path write mark; In this invention, the current temporary relationship status consists of the current relationship placeholder, the relationship trial slot write flag, the lock propagation path write flag, and the release propagation path write flag. The "not written back" state is the state where the current relationship placeholder has not yet been written to the lock propagation path; the value of the "not written back" state is 0, and the value of the "written back" state is 1. The relationship trial slot write flag is the record value indicating whether the relationship trial slot has been written to the trial propagation path. The lock propagation path write flag is the record value indicating whether the lock propagation path has been written. The release propagation path write flag is the record value indicating whether the release propagation path has been written. Clearing the above write flags means setting the relationship trial slot write flag, the lock propagation path write flag, and the release propagation path write flag to 0. A flag value of 0 indicates that it has not been written, and a flag value of 1 indicates that it has been written. Before the closed propagation path is written back, the temporary relationship status in this round only records the relationship edge markers passed through by the trial propagation path in the relationship trial sowing slot, and the relationship edges in the pre-built agricultural technology knowledge graph are not updated; In this invention, the relation edge marker is a temporary identifier that records the test broadcast propagation path through the relation edge in this round of retrieval. The relation edge marker includes relation type, starting node, ending node and propagation direction. After the locking propagation path is written back, the relation edges traversed by the locking propagation path are marked as locking relation edges in this round. When subsequent combination trial broadcasts in this round traverse the locking relation edges in this round, the corresponding trial broadcast propagation path is marked as a locking propagation path.

[0024] In this invention, the current round of locking relationship edge is the record result of the relationship edge traversed by the locking propagation path in the current round temporary relationship state; after the locking propagation path is written back, the written-back state of the current round relationship occupier to which the current round locking relationship edge belongs is set to 1.

[0025] In this implementation, the agricultural technology retrieval question is broken down into crop scenario anchors and symptom fact anchors, specifically including: Based on the scene adaptation relationship edge and the fact pointing relationship edge within the current retrieval and dissemination entry point, the agricultural technology retrieval question is divided into two anchors. In this invention, the dual-anchor segmentation is the operation of writing the search terms into the crop scene anchor and the symptom fact anchor respectively, based on the type of relation edge hit by the search term. Search terms that match the scene adaptation relationship edge are written into the crop scene anchor, and search terms that match the fact pointing relationship edge are written into the symptom fact anchor. The crop scene anchor is connected to the current round of retrieval propagation entry along the scene adaptation relationship edge that is hit; the symptom fact anchor is connected to the current round of retrieval propagation entry along the fact pointing relationship edge that is hit. Search terms that do not match the scene adaptation relationship edge are not written to the crop scene anchor, and search terms that do not match the fact pointing relationship edge are not written to the symptom fact anchor.

[0026] In this invention, a miss occurs when the search term does not match the starting node name, ending node name, or relation type name of the corresponding relation edge.

[0027] In this implementation, a combined trial planting is performed on the adjacent relationship edges between the crop scene anchor and the symptom fact anchor, specifically including: The crop scene anchor forms a scene-side trial broadcast propagation path along the hit scene adaptation relationship edge, and the symptom fact anchor forms a fact-side trial broadcast propagation path along the hit fact pointing relationship edge; In this invention, the scene-side trial propagation path is a temporary path record consisting of a crop scene anchor, the hit scene adaptation relationship edge, the propagation direction, and the corresponding combined propagation vector; the fact-side trial propagation path is a temporary path record consisting of a symptom fact anchor, the hit fact pointing relationship edge, the propagation direction, and the corresponding combined propagation vector. Write the scene-side test broadcast propagation path and the fact-side test broadcast propagation path into the relationship test broadcast slot, and add an unaggregated mark to the scene-side test broadcast propagation path and the fact-side test broadcast propagation path; In this invention, adding an unaggregated marker means setting the unaggregated markers of the scene-side test broadcast propagation path and the fact-side test broadcast propagation path to 1; The relationship test broadcast slot keeps the entrance to the neighborhood aggregation closed, and the scene-side test broadcast propagation path with the unaggregated marker and the fact-side test broadcast propagation path only advance to the pest and disease node; After the double anchor closure is completed, remove the unaggregated markers from the scenario-side test broadcast propagation path and the fact-side test broadcast propagation path that have completed the double anchor closure. Test broadcast propagation paths whose unaggregated markers have not been removed will not enter the prevention and control measures node.

[0028] In this invention, removing the unaggregated markers means setting the unaggregated markers of the scene-side test broadcast propagation path and the fact-side test broadcast propagation path that have completed double anchor closure to 0.

[0029] In this embodiment, the double-anchor closure specifically includes: The scene-side test broadcast propagation path is written into the scene-side arrival position of the pest and disease node, and the fact-side test broadcast propagation path is written into the fact-side arrival position of the pest and disease node. In this invention, the scene-side arrival position is a temporary record position in the pest and disease node that records the arrival status of the scene-side trial sowing propagation path; the fact-side arrival position is a temporary record position in the pest and disease node that records the arrival status of the fact-side trial sowing propagation path. Both the scene-side arrival position and the fact-side arrival position are initially 0, and are set to 1 after being written. When there are write records for both the scene-side arrival location and the fact-side arrival location within the same pest and disease node, a double-anchor closure mark is generated after the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are matched. In this invention, the record to be written is a record in which the value of the scene-side arrival position or the fact-side arrival position is 1; the snapping is to merge the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path corresponding to the same pest node into a double-anchor closed propagation path; The double-anchor closure marker is a status record after the scene-side trial propagation path and the fact-side trial propagation path of the same pest node are matched. The initial value of the double-anchor closure marker is 0; when there are write records at both the scene-side arrival position and the fact-side arrival position within the same pest node, the double-anchor closure marker is set to 1; when there are write records at only the scene-side arrival position or only the fact-side arrival position, the double-anchor closure marker remains 0. Pest and disease nodes with double-anchor closed tags are retained as double-anchor closed pest and disease nodes, and the unaggregated tags of the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are removed. When only the scene-side arrival position has a write record, the scene-side test broadcast propagation path is marked as a latched propagation path; when only the fact-side arrival position has a write record, the fact-side test broadcast propagation path is marked as a latched propagation path.

[0030] In this embodiment, the pest and disease node with double-anchor closure is used as the entry point. The CompGCN combined propagation structure advances along the control measure node and agricultural input node to the agricultural input restriction relationship, specifically including: Pest and disease nodes marked with double anchor closures have open control measures; pest and disease nodes without double anchor closures do not have open control measures. In this invention, a pest node with a double-anchor closed marker is a pest node with a double-anchor closed marker having a value of 1; the control measure relationship is the relationship edge connecting the pest node and the control measure node in the pre-built agricultural technology knowledge graph, and the propagation direction is from the pest node to the control measure node. An open control measure relationship is achieved by setting the control measure relationship propagation marker to 1; a closed control measure relationship is achieved by keeping the control measure relationship propagation marker at 0. When the control measure relationship propagation marker is 1, the double-anchor closed propagation path enters the control measure node along the control measure relationship; when the control measure relationship propagation marker is 0, the double-anchor closed propagation path does not enter the control measure node. The scenario-side test broadcast propagation path with double-anchor closure markers and the fact-side test broadcast propagation path are merged into the double-anchor closure propagation path; In this invention, the scenario-side trial propagation path and the fact-side trial propagation path with double anchor closure markers are two trial propagation paths associated with a double anchor closure marker with a value of 1 after being snapped together within the same pest node; merging into the double anchor closure propagation path means merging the temporary path record of the scenario-side trial propagation path and the temporary path record of the fact-side trial propagation path into the same double anchor closure propagation path. The double-anchor closed propagation path enters the prevention and control measure node along the relationship between prevention and control measures, and enters the agricultural input node along the relationship between the application of agricultural inputs. In this invention, the agricultural input application relationship is the relationship edge connecting the prevention and control measure node and the agricultural input node in the pre-built agricultural technology knowledge graph, and the propagation direction is from the prevention and control measure node to the agricultural input node; The dual-anchor closed propagation path advances from the agricultural input node to the agricultural input prohibition and restriction relationship. When the prevention and control measure relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path. When the agricultural input applicability relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path.

[0031] In this invention, a missing control measure relationship means that the pest and disease node in the double-anchor closed loop is not connected to a control measure relationship; a missing agricultural input application relationship means that the control measure node is not connected to an agricultural input application relationship. When a relationship is missing, the locking flag of the double-anchor closed propagation path is set to 1.

[0032] In this embodiment, a reverse backtracking is performed along the agricultural input restriction and prohibition relationship towards the crop scenario anchor, specifically including: When the double-anchor closed propagation path reaches the agricultural input restriction / prohibition relationship, it turns into a reverse turnback; In this invention, switching to reverse reversal means stopping the continued backward propagation and changing the double-anchor closed propagation path to reverse verification according to the recorded propagation order; The reverse turnback follows the agricultural input restriction and prohibition relationship back to the crop scene anchor; When the reverse return hits the crop scene anchor and does not trigger the restriction state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as the release propagation path; In this invention, the crop scene anchor is the node reached when the reverse turn stops and is consistent with the crop scene anchor; When the reverse return fails to hit the crop scene anchor, the double-anchor closed propagation path is marked as a locked propagation path; In this invention, a missed crop scene anchor means that the node reached when the reverse turn stops is inconsistent with the crop scene anchor; When the reverse return triggers the restricted state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as a locked propagation path.

[0033] In this embodiment, the write-back of the blocking propagation path to the current round's temporary relationship state specifically includes: Mark the edges along the locking propagation path as the locking relationship edges in this round; A blocking source marker is generated based on the location where the blocking propagation path is formed. The blocking source marker is one of the following: single-path arrival blocking marker, relationship missing blocking marker, backtracking miss blocking marker, and restriction state triggered blocking marker. In this invention, the formation position of the lockout propagation path is the judgment position at which the lockout propagation path is formed. A single-path arrival lockout marker is a lockout source marker generated when only the scene-side arrival position has a written record or only the fact-side arrival position has a written record; a relationship-missing lockout marker is a lockout source marker generated when the prevention and control measure relationship or the agricultural input application relationship is missing; a reverse return miss lockout marker is a lockout source marker generated when the reverse return fails to hit the crop scene anchor; a restriction state trigger lockout marker is a lockout source marker generated when the reverse return triggers the restriction state recorded in the agricultural input restriction relationship. Write the locking source marker and the propagation direction of the locking propagation path into the locking relationship edge in this round; When subsequent combination test broadcasts pass through the locking relationship edge of this round, the test broadcast propagation path whose propagation direction is consistent with the propagation direction recorded in the locking relationship edge of this round is marked as the locking propagation path.

[0034] In this invention, the propagation direction is consistent because the propagation direction recorded in the trial propagation path is the same as the propagation direction recorded in the current round of locking relationship edges.

[0035] In this embodiment, the release of the propagation path is written into the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot, specifically including: The crop scene anchors, symptom fact anchors, double-anchor closed pest and disease nodes, prevention and control measure nodes, agricultural input nodes, and agricultural input restriction and prohibition relationships along the transmission path are written into the evidence path slot in the order of transmission. In this invention, writing according to the propagation order means writing according to the order of the nodes and relation edges recorded in the release propagation path; The double-anchor closure marker, the reverse return record of the crop scene anchor, and the verification record of the restriction status that does not trigger the agricultural input restriction relationship are written into the evidence path slot; In this invention, the turnaround record is a path record of returning from the agricultural input restriction relationship to the crop scene anchor in reverse, including the turnaround start point, the nodes passed through, and the stop node; the verification record is a record formed after verifying the restriction status recorded in the agricultural input restriction relationship. The evidence path slots form an evidence chain according to the propagation order of the release propagation path; In this invention, the evidence chain is a set of path records arranged in the evidence path slot according to the propagation order of the release propagation path; In the chain of evidence, the double-anchored closed pest and disease node is used as the search hit node, the prevention and control measure node is used as the search measure node, the agricultural input node is used as the search agricultural input node, and the agricultural input prohibition and restriction relationship is used as the search restriction relationship. In this invention, the search hit node is the pest and disease object in the agricultural technology knowledge search results; the search measure node is the prevention and control operation object in the agricultural technology knowledge search results; the search agricultural input node is the agricultural input object in the agricultural technology knowledge search results; and the search restriction relationship is the agricultural input restriction record in the agricultural technology knowledge search results. Agricultural technology knowledge retrieval results are generated based on search hit nodes, search measure nodes, search agricultural input nodes, and search restriction relationships.

[0036] An agricultural technology knowledge retrieval service system based on a knowledge graph according to an embodiment of the present invention includes the following modules: The graph loading module is used to load the pre-built agricultural technology knowledge graph into the CompGCN combinatorial propagation structure, lock the entry point of the current round of retrieval and propagation, and initialize the temporary relationship state of the current round. The dual-anchor access module is used to split agricultural technology retrieval questions into crop scenario anchors and symptom fact anchors, and respectively access scenario adaptation relationship edges and fact pointing relationship edges; The combined trial broadcast module is used to perform combined trial broadcasts on the relation edges adjacent to the crop scene anchor and the symptom fact anchor, write the trial broadcast propagation path into the relation trial broadcast slot, and close the entrance of the relation trial broadcast slot to the neighborhood aggregation. The trial sowing advancement module is used to advance the trial sowing propagation path from the relationship trial sowing slot to the disease and pest node, execute double anchor closure, and mark the closed propagation path; The measures advancement module is used to advance from the pest and disease node with double-anchor closure as the entry point, along the prevention and control measures node and agricultural input node to the agricultural input restriction relationship; The reverse turnaround module is used to perform a reverse turnaround along the agricultural input restriction relationship to the crop scene anchor, marking the release propagation path and the locking propagation path; The write-back output module is used to write back the locking propagation path to the current round's temporary relationship state, write the release propagation path into the evidence path slot, and generate agricultural technology knowledge retrieval results.

[0037] Example 1: To verify the feasibility of this invention in practice, it was applied to an agricultural technology knowledge retrieval service scenario. In this scenario, the questions entered by farmers are no longer standardized names of pests and diseases, but rather natural language content containing crop information, symptoms, and concerns about pesticide use. Common query text formats include "Tomato leaves are curled and yellowing, with brown spots on the fruit surface; I want to find control methods and available agricultural inputs," and "Rice leaf tips are yellowing, with small spots on the leaf surface; the field humidity is too high; can I use a certain type of pesticide?" Traditional keyword searches easily capture words like "yellowing," "brown spots," and "pesticides," directly returning several disease and agricultural input names. The crop scenario, symptom facts, and restrictions on agricultural inputs are not checked in the same chain of evidence. The results may contain pests and diseases that only match the symptoms but not the planting scenario, and there may also be cases where control measures do not match agricultural input restrictions.

[0038] In this embodiment, the pre-built agricultural technology knowledge graph includes crop nodes, symptom nodes, pest and disease nodes, control measure nodes, and agricultural input nodes. The test sample consists of 1200 anonymized agricultural technology query texts, covering 34 types of crops, 92 types of pests and diseases, 186 control measures, 117 agricultural input nodes, and 214 agricultural input restriction / prohibition relationships. Each query is manually annotated with the correct pest or disease, adoptable control measures, available agricultural inputs, and restriction / prohibition information as verification criteria. The comparison method uses traditional keyword retrieval and conventional knowledge graph retrieval; the method of this invention uses crop scenario anchors, symptom fact anchors, combined trial planting, double anchor closure, reverse loop of agricultural input restriction / prohibition relationships, and evidence path slot output.

[0039] In application, the system first breaks down agricultural technology retrieval questions into crop scenario anchors and symptom fact anchors. Taking "There are small insects on the back of cucumber leaves, and the leaves are turning pale; I want to find out how to control them" as an example, the crop scenario anchor carries "cucumber," and the symptom fact anchor carries "small insects, pale leaves." The crop scenario anchor enters the graph along the scenario adaptation relationship edge, and the symptom fact anchor enters the graph along the fact pointing relationship edge. The two trial propagation paths are first written into the relationship trial propagation slot, and do not directly enter the neighborhood aggregation, to avoid a single symptom bringing unrelated pest and disease nodes into the results prematurely. After the trial propagation path reaches the pest and disease node, only when the same pest and disease node simultaneously receives both the crop scenario anchor propagation path and the symptom fact anchor propagation path will a double anchor closure be formed. If only the symptom side arrives, the path is marked as a closed propagation path and does not enter the subsequent control measure node.

[0040] After the double anchor closure, the system proceeds along the prevention and control measures relationship to the prevention and control measures node, and then along the agricultural input application relationship to the agricultural input node. Upon reaching the agricultural input restriction relationship, the system does not directly output the agricultural input name, but instead reverses along the agricultural input restriction relationship back to the crop scene anchor. Only when the reverse reversal hits the crop scene anchor, and the agricultural input restriction relationship has not triggered a prohibited state, restricted state, or safe interval state, is the double anchor closure propagation path marked as a release propagation path. If the reverse reversal does not return to the crop scene anchor, or the agricultural input restriction relationship triggers a restricted state, the path is locked and not written into the evidence path slot. Thus, the output result is not just "disease / pest name + pesticide name", but a complete evidence chain including the crop scene anchor, symptom fact anchor, disease / pest node, prevention and control measures node, agricultural input node, and agricultural input restriction relationship.

[0041] In 1200 query samples, traditional keyword retrieval is sensitive to symptom terms, but the false hit rate for single-path symptom searches reaches 18.7%. Conventional knowledge graph retrieval can utilize node connections, reducing the false hit rate to 13.1%, but it still sometimes matches only symptoms without verifying the crop context. This invention closes both the context-side path and the fact-side path to the same pest / disease node before proceeding, reducing the false hit rate for single-path symptom searches to 4.6%. In terms of matching prevention and control measures, the accuracy rate of traditional keyword retrieval is 76.2%, conventional knowledge graph retrieval is 84.5%, and this invention reaches 93.8%. The false recommendation rate for prohibited and restricted agricultural inputs decreased from 5.4% in conventional knowledge graph retrieval to 0.9%, mainly because this invention adds a reverse loop of prohibited and restricted agricultural input relationships after the agricultural input node, locking paths that fail to pass crop context anchor verification or trigger restriction states.

[0042] Table 1: Comparison of the effects of double-anchor closure and reverse return retrieval

[0043] The above data were obtained under the same test sample set and the same manually labeled benchmark. The data in the table reflects that the main improvement of this invention lies not in simply increasing the number of returned results, but in reducing the number of erroneous paths leading to the results. While traditional keyword retrieval has a faster response speed, its interpretability is only 41.3%, with many results only showing the matched words and failing to reveal the connection chains between crop scenarios, pests and diseases, control measures, and agricultural input restrictions. Conventional knowledge graph retrieval improves the interpretability to 66.7%, but lacks closed-loop control for paths hitting unilateral symptoms, and the verification of agricultural input restrictions is insufficient. This invention, through relational trial planting slots, double-anchor closure, and reverse feedback, blocks erroneous propagation paths before output, achieving an interpretability of 94.5%.

[0044] In terms of search quality, the crop scenario and symptom co-hit rate of this invention reached 91.6%, an improvement of 10.8 percentage points compared to conventional knowledge graph retrieval; the adoption rate by agricultural technicians reached 89.4%, an improvement of 12.5 percentage points compared to conventional knowledge graph retrieval. The average search time was 2.31 seconds, an increase of 0.13 seconds compared to conventional knowledge graph retrieval, but this resulted in a lower rate of incorrect recommendations for prohibited or restricted agricultural inputs and a lower rate of rejection after manual review. For agricultural technical service scenarios, this increase in time is still within the range of online response, resulting in more reliable results, making it particularly suitable for search scenarios with crop differences, similar symptoms, and restrictions on the use of agricultural inputs.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for agricultural technology knowledge retrieval service based on knowledge graphs, characterized in that, Includes the following steps: The pre-built agricultural technology knowledge graph is loaded into the CompGCN combinatorial propagation structure, the entry point for this round of retrieval and propagation is locked, and the temporary relation state for this round is initialized. The agricultural technology retrieval problem is broken down into crop scenario anchors and symptom fact anchors. Crop scenario anchors are connected to scenario adaptation relationship edges, and symptom fact anchors are connected to fact pointing relationship edges. Perform a combined trial broadcast on the relation edges adjacent to the crop scene anchor and the symptom fact anchor. Write the trial broadcast propagation path into the relation trial broadcast slot and close the entrance to the neighborhood aggregation of the relation trial broadcast slot. The trial sowing propagation path is advanced from the relationship trial sowing slot to the pest and disease node. When the pest and disease node simultaneously receives the crop scene anchor propagation path and the symptom fact anchor propagation path, double anchor closure is performed. When the pest and disease node only receives a single propagation path, the single propagation path is marked as a closed propagation path. Taking the double-anchored closed pest and disease node as the entry point, the CompGCN combined propagation structure advances along the control measures node and agricultural input node to the agricultural input restriction relationship; Perform a reverse backtracking along the agricultural input restriction relationship towards the crop scene anchor. If the reverse backtracking hits the crop scene anchor but does not trigger the restriction state recorded in the agricultural input restriction relationship, it is marked as a release propagation path. If the reverse backtracking does not hit the crop scene anchor, it is marked as a locked propagation path. If the reverse backtracking triggers the restriction state recorded in the agricultural input restriction relationship, it is marked as a locked propagation path. The closed propagation path is written back to the current temporary relationship state, the released propagation path is written to the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot.

2. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 1, characterized in that, The initialization of the current round's temporary relationship state specifically includes: Establish positional entries for this round of retrieval and dissemination based on the relationship types in the pre-built agricultural technology knowledge graph; Set the current relationship placeholder as the current temporary relationship state, set the current temporary relationship state to the non-write-back state, and clear the relationship trial slot write mark, the locked propagation path write mark, and the released propagation path write mark; Before the closed propagation path is written back, the temporary relationship status in this round only records the relationship edge markers passed through by the trial propagation path in the relationship trial sowing slot, and the relationship edges in the pre-built agricultural technology knowledge graph are not updated; After the locking propagation path is written back, the relation edges traversed by the locking propagation path are marked as locking relation edges in this round. When subsequent combination trial broadcasts in this round traverse the locking relation edges in this round, the corresponding trial broadcast propagation path is marked as a locking propagation path.

3. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 1, characterized in that, The agricultural technology retrieval question is broken down into crop scenario anchors and symptom fact anchors, specifically including: Based on the scene adaptation relationship edge and the fact pointing relationship edge within the current retrieval and dissemination entry point, the agricultural technology retrieval question is divided into two anchors. Search terms that match the scene adaptation relationship edge are written into the crop scene anchor, and search terms that match the fact pointing relationship edge are written into the symptom fact anchor. The crop scene anchor is connected to the current round of retrieval propagation entry along the scene adaptation relationship edge that is hit; the symptom fact anchor is connected to the current round of retrieval propagation entry along the fact pointing relationship edge that is hit. Search terms that do not match the scene adaptation relationship edge are not written to the crop scene anchor, and search terms that do not match the fact pointing relationship edge are not written to the symptom fact anchor.

4. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 3, characterized in that, The process of performing a combined trial broadcast on the adjacent edges of the crop scene anchor and the symptom fact anchor specifically includes: The crop scene anchor forms a scene-side trial broadcast propagation path along the hit scene adaptation relationship edge, and the symptom fact anchor forms a fact-side trial broadcast propagation path along the hit fact pointing relationship edge; Write the scene-side test broadcast propagation path and the fact-side test broadcast propagation path into the relationship test broadcast slot, and add an unaggregated mark to the scene-side test broadcast propagation path and the fact-side test broadcast propagation path; The relationship test broadcast slot keeps the entrance to the neighborhood aggregation closed, and the scene-side test broadcast propagation path with the unaggregated marker and the fact-side test broadcast propagation path only advance to the pest and disease node; After the double anchor closure is completed, remove the unaggregated markers from the scenario-side test broadcast propagation path and the fact-side test broadcast propagation path that have completed the double anchor closure. Test broadcast propagation paths whose unaggregated markers have not been removed will not enter the prevention and control measures node.

5. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 4, characterized in that, The double-anchor closure specifically includes: The scene-side test broadcast propagation path is written into the scene-side arrival position of the pest and disease node, and the fact-side test broadcast propagation path is written into the fact-side arrival position of the pest and disease node. When there are write records for both the scene-side arrival location and the fact-side arrival location within the same pest and disease node, a double-anchor closure mark is generated after the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are matched. Pest and disease nodes with double-anchor closed tags are retained as double-anchor closed pest and disease nodes, and the unaggregated tags of the scene-side trial broadcast propagation path and the fact-side trial broadcast propagation path are removed. When only the scene-side arrival position has a write record, the scene-side test broadcast propagation path is marked as a latched propagation path; when only the fact-side arrival position has a write record, the fact-side test broadcast propagation path is marked as a latched propagation path.

6. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 5, characterized in that, The CompGCN combined propagation structure, using the double-anchored closed pest and disease node as the entry point, advances along the control measure node and agricultural input node to the agricultural input restriction relationship, specifically including: Pest and disease nodes marked with double anchor closures have open control measures; pest and disease nodes without double anchor closures do not have open control measures. The scenario-side test broadcast propagation path with double-anchor closure markers and the fact-side test broadcast propagation path are merged into the double-anchor closure propagation path; The double-anchor closed propagation path enters the prevention and control measure node along the relationship between prevention and control measures, and enters the agricultural input node along the relationship between the application of agricultural inputs. The dual-anchor closed propagation path advances from the agricultural input node to the agricultural input prohibition and restriction relationship. When the prevention and control measure relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path. When the agricultural input applicability relationship is missing, the dual-anchor closed propagation path is marked as a closed propagation path.

7. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 6, characterized in that, The reverse backtracking along the agricultural input restriction and prohibition relationship to the crop scenario anchor specifically includes: When the double-anchor closed propagation path reaches the agricultural input restriction / prohibition relationship, it turns into a reverse turnback; The reverse turnback follows the agricultural input restriction and prohibition relationship back to the crop scene anchor; When the reverse return hits the crop scene anchor and does not trigger the restriction state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as the release propagation path; When the reverse return fails to hit the crop scene anchor, the double-anchor closed propagation path is marked as a locked propagation path; When the reverse return triggers the restricted state recorded in the agricultural input restriction relationship, the double-anchor closed propagation path is marked as a locked propagation path.

8. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 7, characterized in that, The write-back of the latch propagation path to the current round's temporary relation state specifically includes: Mark the edges along the locking propagation path as the locking relationship edges in this round; A blocking source marker is generated based on the location where the blocking propagation path is formed. The blocking source marker is one of the following: single-path arrival blocking marker, relationship missing blocking marker, backtracking miss blocking marker, and restriction state triggered blocking marker. Write the locking source marker and the propagation direction of the locking propagation path into the locking relationship edge in this round; When subsequent combination test broadcasts pass through the locking relationship edge of this round, the test broadcast propagation path whose propagation direction is consistent with the propagation direction recorded in the locking relationship edge of this round is marked as the locking propagation path.

9. The method for agricultural technology knowledge retrieval service based on knowledge graphs according to claim 8, characterized in that, The release propagation path is written into the evidence path slot, and agricultural technology knowledge retrieval results are generated based on the evidence path slot, specifically including: The crop scene anchors, symptom fact anchors, double-anchor closed pest and disease nodes, prevention and control measure nodes, agricultural input nodes, and agricultural input restriction and prohibition relationships along the transmission path are written into the evidence path slot in the order of transmission. The double-anchor closure marker, the reverse return record of the crop scene anchor, and the verification record of the restriction status that does not trigger the agricultural input restriction relationship are written into the evidence path slot; The evidence path slots form an evidence chain according to the propagation order of the release propagation path; In the chain of evidence, the double-anchored closed pest and disease node is used as the search hit node, the prevention and control measure node is used as the search measure node, the agricultural input node is used as the search agricultural input node, and the agricultural input prohibition and restriction relationship is used as the search restriction relationship. Agricultural technology knowledge retrieval results are generated based on search hit nodes, search measure nodes, search agricultural input nodes, and search restriction relationships.

10. A knowledge graph-based agricultural technology knowledge retrieval service system, applied to the knowledge graph-based agricultural technology knowledge retrieval service method described in any one of claims 1 to 9, characterized in that, Includes the following modules: The graph loading module is used to load the pre-built agricultural technology knowledge graph into the CompGCN combinatorial propagation structure, lock the entry point of the current round of retrieval and propagation, and initialize the temporary relationship state of the current round. The dual-anchor access module is used to split agricultural technology retrieval questions into crop scenario anchors and symptom fact anchors, and respectively access scenario adaptation relationship edges and fact pointing relationship edges; The combined trial broadcast module is used to perform combined trial broadcasts on the relation edges adjacent to the crop scene anchor and the symptom fact anchor, write the trial broadcast propagation path into the relation trial broadcast slot, and close the entrance of the relation trial broadcast slot to the neighborhood aggregation. The trial sowing advancement module is used to advance the trial sowing propagation path from the relationship trial sowing slot to the disease and pest node, execute double anchor closure, and mark the closed propagation path; The measures advancement module is used to advance from the pest and disease node with double-anchor closure as the entry point, along the prevention and control measures node and agricultural input node to the agricultural input restriction relationship; The reverse turnaround module is used to perform a reverse turnaround along the agricultural input restriction relationship to the crop scene anchor, marking the release propagation path and the locking propagation path; The write-back output module is used to write back the locking propagation path to the current round's temporary relationship state, write the release propagation path into the evidence path slot, and generate agricultural technology knowledge retrieval results.

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