Method for reducing emission of nitrogen and phosphorus in facility vegetable field

Abstract

The invention relates to the technical field of ecological agriculture, and particularly discloses a facility vegetable field nitrogen and phosphorus emission reduction method. According to the method, 40%-60% of inorganic nitrogen fertilizer is replaced with the plant straw and the organic fertilizer, the nitrogen ratio of the inorganic fertilizer to the organic fertilizer to the plant straw is reasonably controlled, the plant straw and the microbial agent are buried into the cultivated soil, and then transplanting and cultivation are conducted. Wherein the technology of deeply burying the straw and applying the microbial inoculum accurately matches the space-time law of crop nutrient requirements, and realizes the transformation from passive fertilization to active fertilizer adjustment. According to the facility vegetable field nitrogen and phosphorus emission reduction method, the adverse effect on the environment is remarkably reduced while fertilizer use is optimized and the crop yield and the dry matter accumulation amount are increased, and the facility vegetable field nitrogen and phosphorus emission reduction method is an innovative planting management mode with economic benefits and environmental benefits; and a green and efficient new path is provided for greenhouse vegetable planting, especially greenhouse tomato planting.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological agriculture and relates to a method for reducing nitrogen and phosphorus emissions in a protected vegetable field. Background Art

[0002] At present, the vegetable system is divided into two categories: protected vegetables and open-field vegetables. Protected vegetables have developed rapidly due to their high output value, high intensification level, and being free from seasonal factors. Nitrogen, as an important constituent element of soil nutrients, not only affects soil quality, crop growth conditions, etc., but also affects environmental problems and even global climate change. However, most vegetables are shallow-rooted crops and are sensitive to insufficient soil moisture and nutrients. Therefore, in the process of vegetable production, there are generally problems such as high fertilizer input and unreasonable fertilization patterns, resulting in a large enrichment of available soil nutrients (nitrogen, phosphorus, etc.), a decrease in organic matter content, and a reduction in fertilizer nutrient utilization rate, and bringing a series of ecological environmental pollution problems of soil, water body, and atmosphere. For example, the application of excessive nitrogen fertilizer will promote ammonia volatilization and nitrous oxide (N 2 O) emissions, exacerbating the greenhouse effect, while the loss of phosphate fertilizer and potassium fertilizer may cause ecological risks such as water eutrophication. How to change the traditional fertilization method in protected vegetable production, and rationally and effectively apply nitrogen fertilizer on the premise of ensuring agricultural product yield and environmental safety, and promote the high-quality production and sustainable development of protected vegetables, is an urgent problem to be solved in the current development process of protected vegetables.

[0003] Applying organic fertilizers and seeking reasonable chemical fertilizer reduction and substitution technologies are of great significance to the change of soil fertility, environmental improvement, and ensuring high yield and quality of vegetables during the process of protected vegetable planting. Protected vegetables emphasize the application of livestock and poultry organic fertilizers and neglect the use of straw. There is a large amount of nutrient input and little energy (carbon) input, and the relationship between nutrients and energy is seriously unbalanced, resulting in low soil organic matter content, low nitrogen fertilizer utilization rate, and high nitrogen emissions. In addition, in the prior art, when returning straw to the field, generally mulch return or deep plowing return is used. These two straw return methods have disadvantages such as low decomposition efficiency, difficult nutrient release in the short term, high greenhouse gas emissions, and increased pest and disease risks. In addition, deep plowing return will also disturb the soil structure, resulting in a shallower plow layer and a decline in water and fertilizer retention capacity; repeated mechanical rolling operations will also cause an increase in the bulk density of the plow layer, directly affecting root development and water infiltration efficiency. Summary of the Invention

[0004] Aiming at the problems of resource waste, environmental pollution, and low economic benefits existing in the fertilizer and water management and straw return methods in vegetable planting in the prior art, the present invention combines deep straw burial in the field with controlled-release fertilizers, and provides a method for reducing nitrogen and phosphorus emissions in a protected vegetable field. This method comprehensively considers the fertilizer demand law of vegetables and other crops and the dynamic law of straw decomposition, realizes the matching of water and fertilizer supply and crop demand in time and space, and can simultaneously solve the dual problems of nutrient utilization rate and greenhouse gas emissions while taking into account economic benefits.

[0005] To achieve the above invention objectives, the embodiments of the present invention adopt the following technical solutions: The present invention provides a method for reducing nitrogen and phosphorus emissions in protected vegetable fields, specifically: using plant straw and organic fertilizer to replace 40%-60% of inorganic nitrogen fertilizer; Before cultivating crops, deeply bury the microbial inoculant and the plant straw into the cultivated soil and then cultivate; Calculated by nitrogen, the mass ratio of the plant straw to the inorganic nitrogen fertilizer is 20-30:45-55; Calculated by nitrogen, the total application amount of the plant straw, inorganic nitrogen fertilizer and organic fertilizer is 420 kg / hm 2 -480 kg / hm 2 .

[0006] The method for reducing nitrogen and phosphorus emissions in protected vegetable fields provided by the present invention is an integrated management technology that takes into account water conservation and fertilizer control, efficient utilization of straw, and environmental friendliness. In the present invention, by combining different sources of organic materials and taking the replacement of chemical fertilizer nitrogen as the starting point, and focusing on the nitrogen and phosphorus reduction and control effects in protected vegetable fields, a mode of combining chemical fertilizer nitrogen with different organic materials (manure nitrogen and straw nitrogen) is given, providing a natural solution for the protected agriculture to achieve the green and sustainable goal of efficient combination of planting and breeding.

[0007] In addition, the co-application of deep-buried straw returning to the field and controlled-release fertilizers is considered for the following reasons: the replacement of inorganic fertilizers with plant straw can improve the soil micro-ecological environment, slowly release nitrogen and reduce nutrient loss, promote the carbon-nitrogen synergistic effect, and enhance stress resistance; the organic fertilizer used can provide humus, medium and trace elements and slow-release nutrients, improve the soil aggregate structure, and enhance the water and fertilizer retention capacity. The purpose of moderately deep-burying the plant straw is to match the fertilizer requirement law of crop growth with the slow decomposition and release of straw in time, and couple the downward exploration of crop root growth with the deep-buried straw in space. Through "delaying nitrogen supply in time, storing fertilizer deeply in space, and synergizing the function of bacteria groups", the spatio-temporal law of crop nutrient demand is accurately matched, realizing the transformation from "passive fertilization" to "active fertilizer adjustment", which is an optimized strategy that takes into account high yield, good quality and soil sustainability.

[0008] As the first limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, the depth of burying the plant straw is 10 cm-25 cm from the surface of the cultivated land.

[0009] As the second limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, the microbial inoculant includes at least three of Bacillus subtilis, Bacillus amyloliquefaciens, Saccharomyces cerevisiae, Actinomycetes, Trichoderma or Aspergillus oryzae; The plant straws include at least one of corn straws, wheat straws, sorghum straws, sesame straws or pepper straws; in this invention, corn straws are taken as an example for illustration. Before deep burial, the corn straws are cut into small sections of 4 cm - 6 cm.

[0010] The organic fertilizers include at least one of pig manure, chicken manure, cow manure or sheep manure.

[0011] The different types of added microbial agents act synergistically with the straw decomposing bacteria. While decomposing the carbon framework of the straws, they activate the insoluble phosphorus and potassium in the soil and fix the atmospheric nitrogen, forming a microecological network of "carbon energy supply - synergistic release of nitrogen, phosphorus and potassium". The effective viable count of the microbial agents is not less than 5.0×10 8 CFU / g, and the dosage is 1.5 kg - 2 kg of microbial agents per 1 ton of corn straws.

[0012] As the third limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, the crops include tomatoes.

[0013] As the first limitation of the third limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, in the method for reducing nitrogen and phosphorus emissions in protected tomato vegetable fields, by nitrogen content, the mass ratio of inorganic nitrogen fertilizer: organic fertilizer: plant straw in the applied nitrogen fertilizer is 45 - 55:20 - 30:20 - 30.

[0014] As the second limitation of the third limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, the mass ratio of the applied nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer is 1.8 - 2.2:0.8 - 1.2:2.5 - 3; Among them, the nitrogen fertilizer is calculated by nitrogen content, the phosphorus fertilizer is calculated by phosphorus pentoxide, and the potassium fertilizer is calculated by potassium oxide.

[0015] As the third limitation of the third limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, by phosphorus pentoxide content, the applied phosphorus fertilizer is 180 kg / hm 2 -270 kg / hm 2 ; By potassium oxide content, the applied potassium fertilizer is 585 kg / hm 2 -675 kg / hm 2 .

[0016] As the fourth limitation of the third limitation on the method for reducing nitrogen and phosphorus emissions in protected vegetable fields, before tomato planting, the soil above the depth where the reserved plant straws are to be buried is removed, the microbial agents and plant straws are buried, after backfilling the removed soil, the organic fertilizer is scattered, and the soil is turned over; During the growth period of tomatoes, 18% - 22% of inorganic nitrogen fertilizer, 100% of inorganic phosphorus fertilizer, and 35% - 45% of inorganic potassium fertilizer are applied; when the diameters of the first to fourth clusters of tomato fruits reach 3 cm - 4 cm respectively, the remaining fertilizers are topdressed at least four times along with watering.

[0017] At least four times, preferably 4 - 8 times. For example, if the remaining fertilizer is evenly divided into 4 portions, each portion of the fertilizer is topdressed with watering when the diameter of the first cluster of tomatoes reaches 3 cm, the diameter of the second cluster of tomatoes reaches 4 cm, the diameter of the third cluster of tomatoes reaches 3.5 cm, and the diameter of the fourth cluster of tomatoes reaches 4 cm respectively.

[0018] Further, when turning the soil, the organic fertilizer is turned into the depth of 5 cm - 15 cm from the ground surface, depending on the burial depth of the plant straw, and it is appropriate not to turn out the straw.

[0019] The present invention adopts an efficient fertilizer and water management mode in crop planting. It is intended to achieve the efficient utilization of fertilizers and water resources through reasonable fertilizer operation, application methods, and reasonable water management, reduce production costs, and improve environmental benefits at the same time. After the straw is applied with microbial inoculants and deeply buried, while the external inoculants and the decomposing bacteria inside the straw synergistically decompose the straw carbon framework, the insoluble phosphorus and potassium in the soil are activated, and the atmospheric nitrogen is fixed, forming a "carbon - energy supply - nitrogen, phosphorus, and potassium synergistic release" micro - ecological network. The straw deep - burial technology realizes the matching with the nutrient requirements of plants at different growth stages by controlling the slow release of nutrients and generating a spatio - temporal optimization effect.

[0020] Among them, using organic fertilizer and plant straw as nitrogen sources to replace part of the inorganic fertilizer can improve the soil micro - ecological environment, slow - release nitrogen supply, reduce nutrient loss, improve the carbon - nitrogen synergistic effect, and enhance the stress resistance of crops. Specifically as follows: (1) Organic nitrogen fertilizers are rich in organic matter and microorganisms, which can activate the indigenous microbial community in the soil, enhance the activity of soil enzymes (such as urease, cellulase), promote the formation of soil aggregate structure, and alleviate the problems of soil compaction and salinization caused by long - term use of chemical fertilizers in protected soils; (2) Organic nitrogen needs to be converted into ammonium nitrogen (NH 4 + )and nitrate nitrogen (NO 3 - )through microbial mineralization, and the release rate is more matched with the nitrogen - demand cycle of tomatoes, avoiding the short - term excessive supply of chemical fertilizer nitrogen leading to root burning or leaching loss (reducing nitrate pollution of groundwater); (3) The carbon - nitrogen ratio (C / N) in organic fertilizers is relatively high (such as the C / N of straw compost is approximately 30 - 50). During the decomposition process, microorganisms need to absorb nitrogen for metabolism. By regulating the C / N ratio (ideally 25 - 30), the humification and mineralization processes can be balanced, avoiding the excessive fixation or rapid release of nitrogen; (4) Active substances such as humic acid and amino acids in organic nitrogen fertilizers can promote the root development and photosynthesis of tomatoes, increase the sugar content and vitamin content of fruits, and at the same time reduce the risk of nitrate accumulation. In addition, the carbon source (C / N 15 - 25:1) in organic nitrogen fertilizers stimulates the proliferation of microorganisms (the number of bacteria increases by 2 - 3 times), accelerating the mineralization of organic nitrogen into NH 4 +Meanwhile, the nitrogen in inorganic nitrogen fertilizers is assimilated and fixed by microorganisms, forming a "fast-slow" alternating nitrogen supply pattern.

[0021] Deep burial of straw has the following effects: (1) Temporal matching of nutrient requirements: Crops such as tomatoes have a relatively low nitrogen demand in the early growth stage (seedling stage to flowering stage), while the nitrogen demand increases significantly after entering the fruit setting stage and fruit swelling stage. In the present invention, the nutrient slow release has a higher fitting degree with the tomato demand curve, controlling nitrogen in the early stage to prevent excessive growth. In the initial stage of decomposition of high C / N straw, microorganisms preferentially utilize soil available nitrogen, inhibiting excessive nitrogen in the seedling stage from causing excessive growth of stems and leaves and promoting root development. Stabilizing nitrogen in the middle and late stages to ensure quality: Mineralized nitrogen from straw is continuously released during the flowering and fruiting stages, combined with the nitrogen fixation effect of the microbial agent, stably supplying nitrogen, reducing nitrate accumulation, and improving the sugar-acid ratio of fruits. In the middle and late stages, nitrogen (NH 4 + / NO 3 - ) is gradually released with mineralization, synchronizing with the nitrogen demand peak during the fruit swelling stage, avoiding the disadvantages of "promoting in the front and declining in the back" of chemical fertilizer nitrogen. (2) Spatial adaptation of nutrient supply: The tomato roots are concentrated in the surface layer (0-20 cm) during the seedling stage and penetrate deeper into the deep layer (30-50 cm) later. In the present invention, the straw is buried in the soil layer of 10 cm - 25 cm. In the initial stage, the nitrogen competition in the surface layer is reduced. Later, as the roots penetrate deeper, the deep-layer mineralized nitrogen can directly supply the demand during the fruit swelling stage, realizing the spatial coupling of the "nutrient reservoir" and the "absorption layer". (3) Temporal and spatial improvement of soil-root interaction: The deep-buried straw forms pore channels during the decomposition process, improving the permeability of the deep soil, inducing the roots to penetrate deeper, and expanding the nutrient absorption range; Water and fertilizer spatial buffering: After the deep-layer straw is humified, it improves the water holding capacity of the soil, reducing nitrogen leaching during the rainy season and supplying water and fertilizer to the upper layer through capillary action during the dry season; Emission reduction and stress resistance enhancement, reducing nitrogen volatilization loss: Deep burial avoids ammonia volatilization (NH 3 ) caused by high temperature on the surface of the straw-covered soil. Combined with the nitrification effect of the microbial agent, ammonium nitrogen is converted into nitrate nitrogen, reducing the loss rate. Generally speaking, the technology of deep burial of straw combined with microbial agents, through "delaying nitrogen supply in time, storing fertilizer deeply in space, and synergistic action of microbial communities in function", precisely matches the temporal and spatial laws of crop nutrient requirements, realizing the transformation from "passive fertilization" to "active fertilizer adjustment", and is an optimized strategy that takes into account high yield, good quality and soil sustainability.

[0022] The nitrogen and phosphorus emission reduction method for protected vegetable fields provided by the present invention can significantly reduce fertilizer input, increase tomato yield, increase the total dry matter accumulation during the whole growth period of tomatoes, improve the effective utilization rate of fertilizers, and reduce nutrient leaching and greenhouse gas emissions compared with the conventional fertilization amount and conventional water and fertilizer management methods commonly used locally.

[0023] In summary, the method for reducing nitrogen and phosphorus emissions in protected vegetable fields provided by the present invention breaks through the limitations of traditional fertilizer and water management habits. While optimizing the fertilizer ratio, increasing the crop yield and dry matter accumulation, it significantly reduces the adverse impact on the environment. It is an innovative planting management model with both economic benefits and environmental friendliness, providing a new green and efficient path for protected vegetable planting, especially for protected tomato planting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of the static chamber used in the determination of nitrous oxide in the present invention; Figure 2 It is the actual burial diagram of the base of the collection chamber and the structural diagram of the collection chamber during the determination of nitrous oxide in the present invention, where Figure 2 (a) represents the actual burial diagram of the base of the collection chamber, Figure 2 (b) represents the structural diagram of the collection chamber; Figure 3 It is the gas chromatogram for determining nitrous oxide in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are preferred examples of the present invention, which are only used to explain the present invention and do not limit the present invention.

[0027] To better illustrate what is provided in the embodiments of the present invention, the following further gives examples through the embodiments.

[0028] The inorganic fertilizer bacteria used in the present invention are commercial chemical fertilizers, and the organic fertilizer is commercial organic fertilizer pig manure. The specific indicators are as follows: Commercial organic fertilizer (dried basis N-P 2 O 5 -K 2 O = 1.764%-2.009%-2.361%, water content 25.648%). Greenhouse corn straw (dried basis N-P 2 O 5 -K 2 O = 1.529%-0.392%-1.603%, water content 5.526%). The inorganic fertilizer nitrogen fertilizer is urea (containing 46% N), and the phosphate fertilizer is superphosphate (containing P 2O 5 18%), potassium fertilizer is potassium sulfate (containing K 2 O 51%).

[0029] In order to better explain the present invention, the following four aspects are described here.

[0030] 1. Test site and test soil The experiment in the embodiment of the present invention was conducted at the Dahe Experimental Station of Hebei Academy of Agricultural and Forestry Sciences. The cultivation system was a winter-spring tomato-autumn-winter tomato rotation system. The experiment was conducted in a solar greenhouse. The test soil was a clay loam calcareous brown soil, and the basic soil physical and chemical properties are shown in Table 1.

[0031] Table 1 Physical and chemical properties of tested soil

[0032] 2. How to prevent mutual influence between different groups When planting tomatoes, the present invention divides the area into different plots according to different water and fertilizer management schemes. In order to prevent the water and nutrients in the 100 cm soil of each plot from affecting each other, before the test begins, the soil in the plot is kept in its original state, and the surrounding soil layer is dug out according to the shape of the plot, separated by 4 mm PVC boards, with a burial depth of 100 cm. The PVC boards are fixed with rivets after being coated with universal glue at the joints, with the upper edge of the PVC boards 5 cm above the soil surface, and the surrounding area is backfilled with soil of the corresponding layer. A small drainage lysimeter is installed in the middle of each plot. The lysimeter is 0.6 m high, 0.60 m long × 1.20 m wide, and has an area of ​​0.72 m 2 The lysimeter is buried at a depth of 1.0 m and the upper edge of the lysimeter is 0.4 m from the ground.

[0033] 3. Fertilization method and amount Before planting tomatoes, remove the soil above the predetermined burying depth of plant straw, bury the microbial agent and plant straw, backfill the removed soil, sprinkle organic fertilizer, and turn the soil; when turning the soil, turn the organic fertilizer to a depth of 3 cm-15 cm from the ground surface, preferably without turning out the straw.

[0034] During the growing period of tomatoes, apply 18%-22% inorganic nitrogen fertilizer, 100% inorganic phosphorus fertilizer, and 35%-45% inorganic potassium fertilizer; when the diameters of the 1st to 4th bunches of tomatoes reach 3 cm-4 cm, apply the remaining fertilizer in four times with watering.

[0035] 4. Irrigation method and amount of water In Comparative Example 1, the customary irrigation amount, time, and method were carried out according to the habits of vegetable farmers in vegetable production. In Examples 1-3 and Comparative Examples 2-6, the sub-surface furrow irrigation method was used for watering. According to the suitable soil water content at different growth stages of vegetables, the main range of soil where the roots are distributed, and the change of soil water content, the irrigation time and amount were determined and measured by a water meter to conduct scientific irrigation. Specifically, it is shown in Table 2 below.

[0036] Table 2 Control Table of Irrigation Amount during the Growth Period of Tomato in Solar Greenhouse

[0037] Note: The plot area is 14.4 m 2 (2.4 m × 6 m), and the irrigation amount was determined according to the soil bulk density and field water holding capacity.

[0038] In order to ensure the growth of tomatoes, the present invention gives specific requirements for the water content in different soil layers, that is, the soil water content that should be achieved for each treatment at different stages and different soil layers, and then calculates the watering amount according to the bulk density.

[0039] For the customary irrigation amount, it is considered that the soil layer in different stages is required to be as deep as possible, so as to ensure water supply on the basis of wasteful irrigation. For the optimized water treatment of the present invention, the soil depth considered in different stages is more concentrated on the surface layer, at most 0-60 cm. In this way, according to the root distribution characteristics of the crop, the water content of the corresponding depth is reasonably ensured.

[0040] V. Test Records, Sampling and Determination Items and Methods (1) Determination Method of Physicochemical Indexes of Tomatoes For each plot, 5 tomato plants were selected to record in detail the dry weight of the leaves picked each time, which was used to calculate the dry weight of the leaves picked during the whole growth period of each plot. At the peak harvest period, mature tomato fruits were selected to measure their VC, soluble sugar, and nitrate contents. At the same time, at the harvest period, mature fruits were selected and dried at 60 °C to measure the water content. After harvesting, 2 tomato plants were selected from each plot (when taking the tomato roots, a 40-cm-deep pit was dug around the plant to take out the complete main root system), and the samples were dried at 60 °C to measure the dry matter weight. After the dried samples were ground into powder, their NPK contents were measured.

[0041] For the total nitrogen and total phosphorus in the roots, stems, leaves and fruits of tomatoes, digestion was carried out with sulfuric acid-hydrogen peroxide. Total nitrogen was determined by the distillation and nitrogen determination method after the digestion solution was alkalized, and total phosphorus was determined by the vanadium yellow colorimetric method.

[0042] (2) Determination Method of Greenhouse Gases and Ammonia In order to quantify under different organic substitution modes, we respectively used the static chamber / gas chromatography method, the closed chamber intermittent pumping method and the leaching bucket method to detect nitrous oxide (N 2 2O), ammonia and leaching loss respectively.

[0043] a. Monitoring of greenhouse gas emissions in the protected vegetable system In the farmland ecosystem, the static chamber / gas chromatography method is a commonly used method for observing greenhouse gases at present. The static chamber method uses a special chamber to cover the soil and plants below and keeps it airtight. By measuring the gas concentrations collected at different times in the airtight chamber, the gas emission flux is calculated. As a simple, fast, and economical detection and analysis method, it can directly observe the greenhouse gas emissions of farmland vegetation and can also evaluate the spatial variability of gas emissions through multi-point observations. In the present invention, in order to improve the measurement efficiency, reduce human errors and labor input, a greenhouse gas automatic sampler is adopted. Among them, the structural schematic diagram of the static chamber used for nitrous oxide measurement is as Figure 1 shown.

[0044] The sampling chamber used in the field experiment is composed of a stainless steel base, a middle section chamber, and a top chamber. The actual buried diagram of the sampling chamber base and the structural diagram of the sampling chamber are as Figure 2 shown, where Figure 2 (a) represents the actual buried diagram of the sampling chamber base, Figure 2 (b) represents the structural diagram of the sampling chamber. The base is a tetrahedral frame with specifications of 50 cm×50 cm×15 cm, and there is a sealed water tank at the top. Before crop planting, the sampling chamber bottom is fixed at a depth of 15 cm in the soil, kept balanced with the soil surface, and fixed throughout the crop growth season. The middle section chamber and the top chamber are both tetrahedrons with specifications of 50 cm×50 cm×50 cm. The middle section chamber is closed on all four sides and open at the top and bottom, and the top chamber is closed on all four sides and the top, and there is a sampling tube in the top chamber. The chamber body is made of stainless steel plate. In order to prevent the influence of the external temperature on the temperature inside the chamber, a foam board is wrapped outside the chamber. Gas samples are collected using a 50 mL syringe with a three-way valve in cooperation with an automatic greenhouse gas sampler. After the static chamber is sealed, samples are taken 4 times, and the gas in the chamber is extracted every 10 min (i.e., at the 0th, 10th, 20th, and 30th min after the static chamber is sealed), and the three-way valve on the syringe is closed. After the sampling is completed, it is immediately taken back to the laboratory, and a gas chromatograph analyzer is used to detect the N 2 O concentration.

[0045] Generally, samples are taken 2 times a week, and the sampling frequency is increased after fertilization and irrigation (samples are taken every 1-2 days). During the entire experimental sampling process, the sampling time is all at 9:00 - 11:00 (Beijing time) to reduce the diurnal variation of N 2 O emissions. After each sampling, the sampling chamber is immediately removed from the base to reduce the disturbance to the soil and crops.

[0046] The formula for calculating the N 2 O flux is shown in Formula 1.

[0047] F = dc / dt × V / V 0 × P / P 0 × T 0 / T × H Formula 1 where, dc / dt is the slope of the regression curve of the gas concentration changing with time during sampling; V is the molar volume of the gas to be measured, with the unit of mL·mol –1 ; T is the absolute temperature during sampling, with the unit of K; H is the height of the sampling chamber, with the unit of m; V 0 , P 0 , T 0 are the molar volume of the gas, air pressure and absolute temperature under standard conditions, respectively.

[0048] b. Monitoring of ammonia gas emissions in the protected vegetable system To monitor ammonia emissions under different organic nitrogen fertilizer substitution patterns, the intermittent air extraction method using a closed chamber was used for determination. The specific steps are as follows: Embed the closed chamber about 5 - 7 cm into the topsoil. Water seal the water tank of the closed chamber. Ammonia volatilization is carried out at 7:00 - 9:00 am and 15:00 - 17:00 pm every day. After the morning air extraction ends, uniformly mix the dilute sulfuric acid in the two wash bottles and place it in a 10 mL centrifuge tube for freezing storage. Put newly prepared dilute sulfuric acid before starting the afternoon air extraction. The wash bottle is filled with 100 mL of 0.02 mol / L dilute sulfuric acid solution for absorbing NH 3 . The air exchange frequency in the air exchange chamber is 15 - 20 times per minute, and the ammonia receiving device is 2 250 mL wash bottles connected in series. After the air extraction ends, remove the closed chamber from the plot.

[0049] Measure it every day in the first week after fertilization and irrigation, and measure it once every two days in the second week. After each sampling ends, immediately remove the sampling chamber from the base to reduce the disturbance to the soil and crops. The calculation formula for the ammonia volatilization rate is shown in Formula 2.

[0050] Ammonia volatilization rate = [M / (A × D)] × 10 -2 Formula 2 In the formula, the unit of the ammonia volatilization rate is kg / (hm 2 ·d), M is the amount of NH4 + -N measured by the capture device on average each time, with the unit of mg; A is the cross-sectional area of the capture device, with the unit of m 2 ; D is the time of each continuous capture, with the unit of day.

[0051] c. Monitoring of nitrogen and phosphorus leaching losses in the protected vegetable system The field leaching solution collection device consists of a leaching pan, a PVC pipe, a suction pump, and a plastic pipe. The PVC pipe has a diameter of 16 cm and a length of 1.8 m. It is vertically placed into a pre-dug soil profile, and the bottom is sealed by welding with a PVC board. A layer of square bricks is placed at the bottom of the PVC pipe to ensure its stability, and then the soil is backfilled layer by layer. The liquid extraction pipe is fixed to the bottom of the PVC pipe, then straightened and extended 30 cm above the ground, and then connected to a sampling bottle, a buffer bottle, and a suction pump. The landfill depth of the PVC pipe is 100 cm. The advantage of this device is that it can directly observe the leaching situation of soil solution, which is convenient for better grasping the sampling time. At the same time, it can observe the change of nutrient content in the leaching solution at different soil depths. After irrigation, measure the height of the irrigation water surface and take samples. Measure the leaching water volume 5 days after irrigation, take a certain volume of water samples, and store them at low temperature. The calculation formulas for the total nitrogen loss and phosphorus loss are shown in the following formulas 3 - 4.

[0052] Total nitrogen loss = volume of leaching water sample × total nitrogen concentration Formula 3 Phosphorus loss = volume of leaching water sample × phosphorus concentration Formula 4 In the formula, the units of total nitrogen loss and phosphorus loss are mg, the unit of the volume of leaching water sample is L, and the units of total nitrogen concentration and phosphorus concentration are mg / L.

[0053] Example 1 In this example, taking tomato - Jingtian Youmi (planting density is 2400 plants per mu) as an example, a method for reducing nitrogen and phosphorus emissions in protected vegetable fields is provided, specifically including: Tomato planting method: autumn - winter season tomatoes - winter - spring season tomatoes. In the present invention, the tomato planting time (transplanting) is August 15, 2023. There are 4 rows of tomatoes planted in each plot, with 12 plants in each row, row spacing of 0.60 m, and plant spacing of 0.50 m. The tomato pulling time is January 24, 2024. The experiment is carried out by technicians with vegetable cultivation experience for daily management of tomatoes, including weeding and regular spraying of pesticides to prevent diseases and pests.

[0054] The nutrient application amount input in the current season is set as follows: taking N - P 2 O 5 -K 2 O into account, the nitrogen fertilizer, phosphate fertilizer, and potassium fertilizer applied per hectare are 450 kg, 225 kg, and 600 kg respectively. The nitrogen fertilizer includes chemical fertilizer, organic fertilizer (pig manure), and corn straw. Calculated by nitrogen, the mass ratio of chemical fertilizer, pig manure, and corn straw in the nitrogen fertilizer is 5:2.5:2.5.

[0055] For the input organic fertilizer and corn straw, it is necessary to measure their N - P 2 O 5 -K 2 O content and water content to provide accurate data for accurately calculating nutrient input. In this season, the N - P 2 O5 -K 2 O is 1.764% - 2.009 - 2.361% (converted to dry basis), and corn straw contains N - P 2 O 5 -K 2 O is 1.529% - 0.392% - 1.603% (dry basis). The water content of organic fertilizer is 25.648%, and the water content of straw is 5.526%. Among them, the specific NPK nutrient input amounts of chemical fertilizers, organic fertilizer pig manure, and straw in the designed treatment in this example are shown in Table 3 as follows.

[0056] Table 3 Statistical table of NPK nutrient input amounts of chemical fertilizers, organic fertilizer pig manure, and straw in Example 1

[0057] Before transplanting tomato seedlings, cut the corn straw to about 5 cm, mix the two according to the ratio of using 2 kg of microbial inoculant per 1 ton of corn straw, and bury it 20 cm below the ground surface; when turning the soil, turn the organic fertilizer pig manure into the soil at a depth of 10 cm - 15 cm from the ground surface. The microbial inoculant selected in this example is the organic material composting agent of "Zhongnong Lvkang", and the effective viable count of this inoculant is 2.0×10 9 CFU / g, including Bacillus, yeast, and Trichoderma.

[0058] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization method and fertilization amount" and "IV. Irrigation method and irrigation amount" in the present invention.

[0059] Example 2 In this example, taking tomato - Jingtian Youmi as an example, a method for reducing nitrogen and phosphorus emissions in protected vegetable fields is provided, which is as follows: The planting method of tomatoes, the types and dosages of nutrients input in the current season, the types and dosages of microbial inoculants, the application methods of fertilizers, etc. are the same as those in Example 1. The differences are only as follows: Before transplanting tomato seedlings, cut the corn straw to about 4.5 cm, mix the two according to the ratio of using 2 kg of microbial inoculant per 1 ton of corn straw, and bury it 10 cm below the ground surface; when turning the soil, turn the organic fertilizer pig manure into the soil at a depth of 3 cm - 7 cm from the ground surface. The rest of the management methods are the same as those in Example 1.

[0060] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization method and fertilization amount" and "IV. Irrigation method and irrigation amount" in the present invention.

[0061] Example 3 In this example, taking tomato - Jingtian Youmi as an example, a method for reducing nitrogen and phosphorus emissions in protected vegetable fields is provided, which is as follows: The tomato planting method, the type and dosage of nutrients input in the current season, the fertilizer application method, etc. are the same as those in Example 1, except that: before transplanting tomato seedlings, cut the corn straw into about 5.5 cm, mix the two according to the ratio of 1.5 kg of microbial inoculum per 1 ton of corn straw, and bury them 25 cm below the ground surface; when turning the soil, turn the organic fertilizer pig manure into the soil 10 cm - 15 cm below the ground surface. The microbial inoculum selected in this example is the commercially available Yijiayi biological fertilizer fermenter, which includes beneficial bacterial groups such as Bacillus subtilis, Bacillus licheniformis, Bacillus laterosporus, Lactobacillus plantarum, and phosphorus-solubilizing, potassium-solubilizing and nitrogen-fixing bacteria. The remaining management methods are the same as those in Example 1.

[0062] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization Method and Fertilization Amount" and "IV. Irrigation Method and Irrigation Amount" of the present invention.

[0063] Control Example 1 Taking tomato - Jingtian Youmi as an example, this control example provides a method for planting tomatoes in a protected vegetable field, which is as follows: This management method adopts the farmer's customary fertilizer and water management mode, and the fertilizer nutrient dosage is set as follows: taking N-P 2 O 5 -K 2 O as the basis, the input amounts of chemical fertilizer nutrients applied are 900 kg / hm 2 、 675 kg / hm 2 and 600 kg / hm 2 ; taking N-P 2 O 5 -K 2 O as the basis, the input amounts of organic nutrients applied simultaneously are 900 kg / hm 2 、1671.2 kg / hm 2 and 1204.6 kg / hm 2 .

[0064] Among them, the NPK nutrient input amounts of the chemical fertilizer and organic fertilizer pig manure in the designed treatment in this control example are specifically shown in Table 4.

[0065] Table 4 Statistical table of NPK nutrient input amounts of chemical fertilizer, organic fertilizer pig manure and straw in Control Example 1

[0066] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization Method and Fertilization Amount" and "IV. Irrigation Method and Irrigation Amount" of the present invention.

[0067] Control Example 2 This comparative example takes Tomato-Jingtian Youmi as an example to provide a method for reducing nitrogen and phosphorus emissions in a facility vegetable field, as follows: The planting method, management method and NPK amount of tomatoes are the same as those in Example 1, except that: in this comparative example, nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer are all chemical fertilizers, no organic fertilizer or corn stalks are used, and there is no need to bury the stalks deeply; 2 O 5 -K 2 O, the fertilizer nutrient input is 450 kg / hm 2 , 225 kg / hm 2 and 600 kg / hm 2 The dosage is the same as that in Example 1. That is, the specific NPK input amount is shown in Table 5.

[0068] Table 5 Statistics of NPK nutrient input of chemical fertilizer, organic fertilizer, pig manure and straw in comparative example 2

[0069] The fertilization method and amount, irrigation method and amount during the planting process are carried out in accordance with the methods described in "III. Fertilization method and amount" and "IV. Irrigation method and amount" of the present invention.

[0070] Comparative Example 3 This comparative example takes Tomato-Jingtian Youmi as an example to provide a method for reducing nitrogen and phosphorus emissions in a facility vegetable field, as follows: The planting method, management method, and NPK amount of tomatoes are the same as those in Example 1, except that: in this comparative example, nitrogen fertilizer, phosphorus fertilizer, and potash fertilizer are selected from chemical fertilizer and organic fertilizer pig manure, and corn stalks are not used, and there is no need to bury the stalks deeply. In terms of nitrogen content, the mass ratio of chemical fertilizer to pig manure in nitrogen fertilizer is 3:1. That is, the NPK input amount is specifically shown in Table 6.

[0071] Table 6 Statistics of NPK nutrient input of chemical fertilizer, organic fertilizer, pig manure and straw in comparative example 3

[0072] The fertilization method and amount, irrigation method and amount during the planting process are carried out in accordance with the methods described in "III. Fertilization method and amount" and "IV. Irrigation method and amount" of the present invention.

[0073] Comparative Example 4 This comparative example takes Tomato-Jingtian Youmi as an example to provide a method for reducing nitrogen and phosphorus emissions in a facility vegetable field, as follows: The planting method, management method, and the amount of NPK input of tomatoes are the same as those in Example 1, except that: in this comparative example, chemical fertilizers and organic fertilizer pig manure are selected for nitrogen, phosphorus, and potassium fertilizers, corn straw is not used, and there is no need to deeply bury the straw. Calculated by nitrogen content, the mass ratio of chemical fertilizer to pig manure in nitrogen fertilizer is 1:1. That is, the specific NPK input amounts are shown in Table 7 below.

[0074] Table 7 Statistical table of NPK nutrient input amounts of chemical fertilizers, organic fertilizer pig manure, and straw in Comparative Example 4

[0075] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization Method and Fertilization Amount" and "IV. Irrigation Method and Irrigation Amount" in the present invention.

[0076] Comparative Example 5 This comparative example provides a method for reducing nitrogen and phosphorus emissions in a facility vegetable field, taking tomato - Jingtian Youmi as an example, as follows: The planting method, management method, the amount of NPK input, the deep burial depth of corn straw, the type and dosage of microbial inoculant of tomatoes are the same as those in Example 1, except that: in this comparative example, chemical fertilizers and corn straw are selected for nitrogen, phosphorus, and potassium fertilizers, and organic fertilizer pig manure is not used. Calculated by nitrogen content, the mass ratio of chemical fertilizer to corn straw in nitrogen fertilizer is 1:1. That is, the specific NPK input amounts are shown in Table 8 below. The remaining management parameters are the same as those in Example 1.

[0077] Table 8 Statistical table of NPK nutrient input amounts of chemical fertilizers, organic fertilizer pig manure, and straw in Comparative Example 5

[0078] The fertilization method and dosage, irrigation method and irrigation amount during the planting process are carried out according to the methods described in "III. Fertilization Method and Fertilization Amount" and "IV. Irrigation Method and Irrigation Amount" in the present invention.

[0079] Comparative Example 6 This comparative example provides a method for reducing nitrogen and phosphorus emissions in a facility vegetable field, taking tomato - Jingtian Youmi as an example, as follows: The planting method, management method, the type and dosage of nutrients input in the current season, the type and dosage of microbial inoculant, the application method of fertilizers, the cutting length of corn straw, etc. of tomatoes are the same as those in Example 1, except that: in this comparative example, corn straw is not deeply buried, and the cut corn straw is mixed with the microbial inoculant and then covered on the surface of the cultivated soil. The remaining management parameters are the same as those in Example 1.

[0080] Effect Example The present invention measured indicators such as tomato yield, economic benefits of tomatoes, dry matter accumulation and distribution during the whole growth period of tomatoes, NP content in each organ during the whole growth period of tomatoes, NP absorption and distribution relationship during the whole growth period of tomatoes, soil nutrient leaching amount, and greenhouse gas emissions under the nitrogen and phosphorus reduction methods (also known as water and fertilizer management methods) for greenhouse tomatoes provided in Examples 1-3 and Comparative Examples 1-6. Statistical tables of tomato yield, economic benefits of tomatoes, dry matter accumulation during the whole growth period of tomatoes, nitrogen content in each organ at the end of the tomato growing season, phosphorus content in each organ at the end of the tomato growing season, total nitrogen uptake during the whole growth period of tomatoes, total phosphorus uptake during the whole growth period of tomatoes, nutrient concentration in leachate, and greenhouse gas emissions under different nitrogen and phosphorus reduction methods are shown in Tables 9-17. Among them, the gas chromatogram of nitrous oxide in Example 1 is as shown in Figure 3 shown.

[0081] (1) The statistical table of tomato yield under different nitrogen and phosphorus reduction methods for greenhouse tomatoes is shown in Table 9.

[0082] Table 9 Statistical table of tomato yield under different nitrogen and phosphorus reduction methods for greenhouse tomatoes

[0083] As can be seen from Table 9, the yield of Example 1 (70.38±3.58 t / hm²) was significantly higher than that of Comparative Example 1 (60.21±3.34 t / hm²) and Comparative Example 2 (59.12±4.19 t / hm²) ( p <0.05), and the yield increase rates were 16.9% and 19.0% respectively. There was no significant difference between Example 3 (67.88±3.58 t / hm²) and Comparative Example 6 (64.04±3.62 t / hm²), but the yield increased by 10.2% compared with Comparative Example 5 (61.58±2.90 t / hm²). The results showed that optimizing the water-nitrogen ratio (Example 1) could significantly increase the tomato yield, while the modes of Comparative Example 1 and Comparative Example 5 were inefficient.

[0084] (2) The statistical table of economic benefits of tomatoes under different nitrogen and phosphorus reduction methods for greenhouse tomatoes is shown in Table 10.

[0085] Table 10 Statistical table of economic benefits of tomatoes under different nitrogen and phosphorus reduction methods for greenhouse tomatoes

[0086] Note: N, P 2 O 5 、K 2 O, commercial organic fertilizer pig manure, corn straw, and tomato price are 5.00, 5.00, 7.60, 0.60, 0.10, and 2.00 yuan / kg respectively. The irrigation cost is calculated according to 1 m 3Converted to 1 kWh of electricity, each kWh is calculated at 0.5 yuan.

[0087] As can be seen from Table 10, the income of Example 1 (13.08 ± 0.72 ten thousand yuan / hm²) was significantly higher than that of Comparative Example 1 (6.64 ± 0.67 ten thousand yuan / hm²) and Comparative Example 2 (11.02 ± 0.84 ten thousand yuan / hm²) ( p <0.05), and the growth rates were 97.0% and 18.7% respectively. Due to the excessively high fertilizer and water cost (5.4 ten thousand yuan / hm²) in Comparative Example 1, the net income was the lowest. Example 1 maximized economic benefits by reducing the irrigation cost (1 ten thousand yuan / hm²) and increasing the yield, with a 14.2% increase in income compared to Comparative Example 4 (11.45 ± 0.58 ten thousand yuan / hm²).

[0088] (3) The statistical table of the total dry matter accumulation during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes is shown in Table 11.

[0089] Table 11 Statistical table of the total dry matter accumulation during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes

[0090] As can be seen from Table 11, the dry matter accumulation of Example 1 (7015.3 ± 63.1 kg / hm²) was significantly higher than that of Comparative Example 6 (4901 ± 374 kg / hm²) ( p <0.05), with an increase rate of 43.1%. Due to insufficient water and fertilizer in Comparative Example 5 (5659 ± 166 kg / hm²), the dry matter accumulation decreased by 12.0% compared to Example 3 (6430 ± 91.4 kg / hm²). The results showed that balanced water and nitrogen supply (Example 1) significantly promoted plant growth.

[0091] (4) The statistical table of the nitrogen content in each organ of tomatoes at the pulling stage under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes is shown in Table 12.

[0092] Table 12 Statistical table of the nitrogen content in each organ of tomatoes at the pulling stage under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes

[0093] As can be seen from Table 12, the nitrogen content in the fruits of Example 1 (2.09 ± 0.18%) was significantly higher than that of Comparative Example 5 (1.76 ± 0.08%) and Comparative Example 6 (1.73 ± 0.06%) ( p <0.05), and the growth rates were 18.8% and 20.8% respectively. The nitrogen content in the roots of Example 2 (2.59 ± 0.44%) was the highest, with a 76.2% increase compared to Comparative Example 1 (1.47 ± 0.16%). After optimizing the water and nitrogen management through the present invention, the nitrogen accumulation in fruits can be significantly improved by enhancing nitrogen absorption and transport.

[0094] (4)Statistics table of phosphorus content in each organ of tomatoes at the end of the growing season under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities is shown in Table 13.

[0095] Table 13 Statistics table of phosphorus content in each organ of tomatoes at the end of the growing season under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities

[0096] As can be seen from Table 13, the phosphorus content in the roots of Example 1 (0.29 ± 0.07%) was significantly higher than that of Comparative Example 6 (0.16 ± 0.03%) ( p <0.05), with an increase of 81.3%. The phosphorus content in the stems of Comparative Example 4 (0.35 ± 0.05%) was the highest, which was 59.1% higher than that of Example 3 (0.22 ± 0.13%).

[0097] (5)Statistics table of total nitrogen uptake during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities is shown in Table 14.

[0098] Table 14 Statistics table of total nitrogen uptake during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities

[0099] As can be seen from Table 14, the total nitrogen uptake of Example 1 (145 ± 12.5 kg N / hm²) was significantly higher than that of Comparative Example 6 (87 ± 25 kg N / hm²) ( p <0.05), with an increase of 66.7%. Although the nitrogen uptake of Comparative Example 2 (142 ± 22 kg N / hm²) was relatively high, due to high leaching losses (see Table 16 for details), its utilization rate was lower than that of Example 1. Optimizing the water-nitrogen pattern can improve nitrogen use efficiency by reducing leaching.

[0100] (6)Statistics table of total phosphorus uptake during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities is shown in Table 15.

[0101] Table 15 Statistics table of total phosphorus uptake during the whole growth period of tomatoes under the management of nitrogen and phosphorus reduction methods for tomatoes in different facilities

[0102] As can be seen from Table 15, the phosphorus uptake of Example 1 (20.9 ± 0.6 kg P 2 O 5 / hm²) was significantly higher than that of Comparative Example 5 (14.1 ± 1.6 kg / hm²) and Comparative Example 6 (13.9 ± 1.7 kg / hm²) ( p(<0.05), with growth rates of 48.2% and 50.4% respectively. Combining with Table 13, in Comparative Example 4, the phosphorus content in the stems and leaves increased, but the phosphorus accumulation in the fruits did not increase. The results show that a reasonable phosphorus fertilizer ratio can coordinate the distribution of phosphorus and avoid ineffective accumulation.

[0103] (7) The statistical table of the nutrient concentrations in the leachate under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes is shown in Table 16.

[0104] Table 16 Statistical table of the nutrient concentrations in the leachate under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes

[0105] As can be seen from Table 16, the total N concentration in the leachate of Comparative Example 2 (533 mg / L) was significantly higher than that of Example 1 (412.1 mg / L) ( p <0.05), and the nitrogen leaching amount increased by 45.9%. Example 1 reduced nitrogen loss by optimizing the irrigation amount and nitrogen fertilizer management. The results show that excessive irrigation (Comparative Example 2) exacerbated nutrient leaching and reduced the utilization efficiency.

[0106] (8) The statistical table of the greenhouse gas emissions under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes is shown in Table 17.

[0107] Table 17 Statistical table of the greenhouse gas emissions under the management of nitrogen and phosphorus reduction methods for different greenhouse tomatoes

[0108] As can be seen from Table 17, the N 2 O emission of Comparative Example 1 (5.6 ± 0.8 kg N 2 O-N / hm²) was significantly higher than that of Example 1 (1.7 ± 0.2 kg / hm²) ( p <0.05), with an increase rate of 229.4%. The N 2 O emission of Example 3 (1.5 ± 0.2 kg / hm²) was reduced by 46.4% compared with that of Comparative Example 3 (2.8 ± 0.4 kg / hm²) by reducing the nitrogen fertilizer application rate and optimizing irrigation.

[0109] In summary, as can be seen from Tables 9 - 17, on the premise of the same input amount of NPK, compared with Comparative Examples 1 - 6, under the management methods provided by Examples 1 - 3 of the present invention, the yield per hectare of tomatoes increased significantly. Under the farmers' customary fertilization and irrigation management mode, the economic benefit of tomatoes was the worst, only 66,400 yuan / hm 2Compared with the management method of Example 1, in Comparative Example 6, the straw is not deeply buried. The total dry matter accumulation amount during the whole growth period of tomatoes, the nitrogen and phosphorus in the fruits at the end of the tomato growing season, the total nitrogen uptake amount and the total phosphorus uptake amount during the whole growth period of tomatoes are all significantly reduced, and the emissions of greenhouse gases nitrous oxide and ammonia are significantly increased. Generally speaking, compared with other management methods that do not deeply bury straw, do not apply organic fertilizer or straw, the nitrogen and phosphorus emission reduction method for protected tomatoes provided by the embodiments of the present invention can reduce fertilizer input, increase tomato yield, increase the total dry matter accumulation amount during the whole growth period of tomatoes, improve the effective utilization rate of fertilizers, and reduce nutrient leaching and greenhouse gas emissions.

[0110] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reducing nitrogen and phosphorus emissions from vegetable fields, characterized in that: Use plant straw and organic fertilizer to replace 40%-60% of inorganic nitrogen fertilizer; Before cultivating crops, the microbial agent and the plant straw are deeply buried in the cultivated soil for cultivation; In terms of nitrogen, the mass ratio of the plant straw to the inorganic nitrogen fertilizer is 20-30:45-55; In terms of nitrogen, the total application rate of plant straw, inorganic nitrogen fertilizer and organic fertilizer is 420 kg / hm 2 -480 kg / hm 2 .

2. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 1, characterized in that: The plant straw is buried at a depth of 10 cm to 25 cm from the surface of the cultivated land.

3. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 1, characterized in that: The microbial agent comprises at least three of Bacillus subtilis, Bacillus amyloliquefaciens, yeast, actinomycetes, Trichoderma or Aspergillus oryzae; and / or The plant straw comprises at least one of corn straw, wheat straw, sorghum straw, sesame straw or pepper straw; and / or The organic fertilizer includes at least one of pig manure, chicken manure, cow manure or sheep manure.

4. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to any one of claims 1 to 3, characterized in that: The crops include tomatoes.

5. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 4, characterized in that: In terms of nitrogen, the mass ratio of inorganic nitrogen fertilizer: organic fertilizer: plant straw in the applied nitrogen fertilizer is 45-55:20-30:20-30.

6. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 4, characterized in that: The mass ratio of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer applied is 1.8-2.2:0.8-1.2:2.5-3; Wherein, the nitrogen fertilizer is calculated as nitrogen, the phosphorus fertilizer is calculated as phosphorus pentoxide, and the potassium fertilizer is calculated as potassium oxide.

7. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 4, characterized in that: Calculated as phosphorus pentoxide, the amount of phosphate fertilizer applied is 180 kg / hm2 2 -270 kg / hm 2 ; and / or The potassium fertilizer applied was 585 kg / hm2 in terms of potassium oxide. 2 -675 kg / hm 2 .

8. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 4, characterized in that: Before planting tomatoes, remove the soil above the predetermined burying depth of plant straw, bury the microbial agent and plant straw, backfill the removed soil, sprinkle organic fertilizer, and turn the soil; During the growing period of tomatoes, apply 18%-22% inorganic nitrogen fertilizer, 100% inorganic phosphorus fertilizer, and 35%-45% inorganic potassium fertilizer; when the diameters of the 1st to 4th bunches of tomatoes reach 3 cm-4 cm, apply the remaining fertilizer at least four times with watering.

9. The method for reducing nitrogen and phosphorus emissions from vegetable fields according to claim 8, characterized in that: When turning the soil, the organic fertilizer is turned into a depth of 5 cm-15 cm from the ground surface.

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