Ratoon rice three-ear synergistic high-yield cultivation method

Abstract

The invention provides a ratooning rice three-ear synergistic high-yield cultivation method, and belongs to the technical field of ratooning rice high-yield cultivation. According to the method, controlled nitrogen application is taken as a core, and matched agricultural measures such as rolling-resistant variety selection, low-stubble-remaining harvesting, uniform straw scattering and dry-wet alternate irrigation are combined, so that a systematic ratooning rice'three ears' synergistic high-yield cultivation technology mode is constructed, and the method aims at effectively relieving yield reduction loss caused by mechanical rolling, improving the stability and benefit of ratooning rice production and improving the economic benefit of ratooning rice production. And theoretical and technical support is provided for large-scale popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of high-yield cultivation technology of ratooning rice, specifically a method for high-yield cultivation of ratooning rice with three panicles working together. Background Technology

[0002] Ratoon rice, as a highly efficient rice production model that allows for two harvests from one crop, boasts numerous advantages, including saving on seeds, labor, time, land, water, fertilizer, and pesticides. It exhibits significant development potential in regions with abundant light and temperature resources ("more than one season, less than two"). However, current ratoon rice production still faces a series of prominent technical challenges, primarily including a lack of mill-resistant varieties and poor coordination in panicle number, panicle type, and maturity between milled and unmilled rows during mechanical harvesting. These issues severely restrict further improvements in the yield and quality of ratoon rice.

[0003] Previous studies have shown that super rice varieties with strong resistance to trampling and outstanding regeneration ability, such as Weiliangyou 8612, can exhibit good synergistic characteristics of "multiple panicles, large panicles, and uniform panicles" (referred to as "three panicles") during the ratooning season. Moreover, this synergistic effect increases with increasing nitrogen application, thereby significantly improving the yield during the ratooning season. Therefore, how to achieve the synergistic effect of "three panicles" under the premise of nitrogen control has become a key issue that urgently needs to be solved in the high-yield cultivation of ratooning rice. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for high-yield cultivation of three panicles of ratooning rice, which can effectively alleviate yield loss caused by mechanical compaction and improve the stability and efficiency of ratooning rice production.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for high-yield cultivation of three panicles in ratooning rice, comprising the following steps: Calculate the amount of nitrogen to be applied based on the soil fertility level and target yield; apply nitrogen fertilizer in three proportions: bud-promoting fertilizer, seedling-promoting fertilizer, and ear-growing fertilizer; and implement supporting measures such as variety selection, early sowing, early transplanting and early harvesting, reasonable dense planting, even distribution of straw, low stubble, alternating dry and wet irrigation, delayed harvesting and pest control. The soil fertility level is divided into low-yield, medium-yield, and high-yield fields; the nitrogen application rate calculation formulas are as follows: low-yield field: Yn=195+(Xn-X1)×36 / 1.5; medium-yield field: Yn=195+(Xn-X1)×33 / 1.5; high-yield field: Yn=195+(Xn-X1)×30 / 1.5; n is the value of the synergy level corresponding to the soil fertility level; the synergy level is divided into I, II, III, IV, and V, with corresponding values ​​of 1, 2, 3, 4, and 5; X is the target yield of ratooning rice for the soil fertility level; X1, X2, X3, X4, and X5 are the target yields for synergy levels I, II, III, IV, and V, respectively.

[0006] Preferably, the grading method for the synergistic level is to grade and evaluate the rice based on six indicators: the number of effective panicles, the difference between effective panicles, the number of grains per panicle, the difference between grains per panicle, the number of days between the beginning of heading, and the actual yield.

[0007] Preferably, the ratio of nitrogen fertilizer applied three times in the low-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:2:1; the ratio of nitrogen fertilizer applied three times in the medium-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:1:2; and the ratio of nitrogen fertilizer applied three times in the high-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 1:2:2.

[0008] Preferably, the variety is a rice variety that is resistant to rolling and lodging.

[0009] Preferably, the rice variety includes one or more of the following: Weiliangyou 8612, Juliangyou 8612, Weiliangyou 2268, Zhenliangyou 8612, Yongyou 4949, Shaoxiang 100, Zhenliangyou Yingxiangsimiao, Chufengyou Yingxiangsimiao, and Heshuangliangyou 138.

[0010] Preferably, the reasonable planting density is 13,000 holes / mu to 17,000 holes / mu.

[0011] Preferably, the stubble height is 10-20cm.

[0012] Preferably, the alternating wet and dry irrigation includes irrigating with water to a depth of 3-5 cm 7-10 days before harvesting, applying fertilizer to promote bud growth, and waiting for the water to dry naturally; and irrigating with water to a depth of 3-5 cm 3-5 days after harvesting, after the regrowth of buds, applying fertilizer to promote seedling growth, and waiting for the water to dry naturally.

[0013] Preferably, the uniformity of straw return to the field after uniform straw distribution reaches 85% or more.

[0014] Preferably, the pest control measures include strengthening the control of rice stem borers and rice planthoppers in the first and second cropping seasons.

[0015] Compared with the prior art, the present invention has the following advantages: Current ratooning rice production faces problems such as inappropriate variety selection, significant yield losses due to compaction, lack of specialized harvesters, and extensive management. These issues lead to difficulties in coordinating multiple and large panicles in compacted rows and poor uniformity between compacted and uncompacted rows, severely restricting the high, stable, and high yields of ratooning rice. This invention is based on the theory of "three panicles" synergy in ratooning rice. It controls nitrogen application based on soil fertility and target yield, with controlled nitrogen application as the core. By comprehensively integrating measures for multiple panicles (controlled nitrogen application, compaction-resistant varieties, alternating wet and dry conditions, reasonable planting density, and pest control), measures for large panicles (leaving low stubble, controlled nitrogen application, early sowing, early transplanting, and early harvesting), and measures for uniform panicles (controlled nitrogen application, leaving low stubble, and delayed harvesting), it achieves the synergy of multiple and large panicles in ratooning rice. This effectively alleviates yield losses caused by mechanical compaction, reduces the dependence on specialized harvesters in ratooning rice production, fully taps the yield potential of ratooning rice, and promotes high and stable yields. Based on the evaluation method of the three-ear synergy level, this invention found that the synergy of the three ears of the machine-harvested Weiliangyou 8612 variety under the controlled nitrogen application mode increases with the increase of nitrogen (N) application rate. Furthermore, the higher the synergy level, the higher the actual yield in the ratoon season, with an increase in the number of effective ears and grains per ear, while the ear difference and the interval between the first ear and the second ear decrease. Under the controlled nitrogen application mode, the nitrogen application rate decreases with the increase of soil fertility and yield. The synergy level of the three ears in low-yield, medium-yield, and high-yield fields increases from level I to level V, with the nitrogen application rate increasing by 72 kg / hm², respectively. 2 66kg / hm 2 60kg / hm 2 The corresponding actual output increased by 2.95 t / hm. 2 3.05 t / hm 2 3.11 t / hm 2 The number of effective panicles increased by 102.4 panicles / m². 2 107.3 ears / m 2 122.1 ears / m 2 The effective panicle difference showed a downward trend, and the number of grains per panicle increased by 17.6, 13.8 and 11.7 grains respectively. The difference in grains per panicle also showed a downward trend. This indicates that the controlled application of nitrogen in medium and high-yield fields has a better promoting effect on the synergistic effect of the three panicles in ratooning rice, and is more conducive to tapping the high-yield potential of ratooning rice. Attached Figure Description

[0016] Figure 1 This diagram illustrates the growth of rice in the three-panicle synergistic high-yield cultivation method of ratooning rice according to the present invention. In the diagram, A represents the uniform spreading of crushed straw and alternating wet and dry irrigation to promote the construction of multi-panicle populations in the rolled rows; B represents the germination of axillary buds at the basal nodes of the rolled rows to promote seedling growth and large panicles; C represents the retention of low stubble in the non-rolled rows to promote the germination of axillary buds at the basal nodes to promote large panicles; and D represents the high uniformity of growth between the rolled and non-rolled rows. Figure 2This diagram illustrates the growth of rice using traditional ratooning rice cultivation methods. In the diagram, A represents poor emergence in the rolled rows due to the return of the first crop straw strips to the field and continuous flooding after harvest; B represents poor emergence in the rolled rows due to continuous flooding after harvest; C represents small number of grains per panicle and poor uniformity of maturity due to leaving high stubble; and D represents the difference in maturity uniformity between rolled and unrolled rows. Detailed Implementation

[0017] This invention provides a method for high-yield cultivation of three panicles in ratooning rice, the method preferably comprising the following steps: Calculate the amount of nitrogen to be applied based on the soil fertility level and target yield; apply nitrogen fertilizer in three proportions: bud-promoting fertilizer, seedling-promoting fertilizer, and ear-growing fertilizer; and implement supporting measures such as variety selection, early sowing, early transplanting and early harvesting, reasonable dense planting, even distribution of straw, low stubble, alternating dry and wet irrigation, delayed harvesting and pest control. The soil fertility level is divided into low-yield, medium-yield, and high-yield fields; the nitrogen application rate calculation formulas are as follows: low-yield field: Yn=195+(Xn-X1)×36 / 1.5; medium-yield field: Yn=195+(Xn-X1)×33 / 1.5; high-yield field: Yn=195+(Xn-X1)×30 / 1.5; n is the value of the synergy level corresponding to the soil fertility level; the synergy level is divided into I, II, III, IV, and V, with corresponding values ​​of 1, 2, 3, 4, and 5; X is the target yield of ratooning rice for the soil fertility level; X1, X2, X3, X4, and X5 are the target yields for synergy levels I, II, III, IV, and V, respectively.

[0018] In this invention, for low-yield fields, Yn = 195 + (Xn - X1) × 36 / 1.5. Y represents the pure nitrogen application rate (kg / hm²); n represents the value of the "three spikelets" synergy level (Table 1) corresponding to the low-yield field, i.e., values ​​of 1, 2, 3, 4, and 5 for levels I, II, III, IV, and V, respectively; X represents the target yield of ratooning rice (kg / hm²), where X1, X2, X3, X4, and X5 are the target yields for "three spikelets" synergy levels I, II, III, IV, and V, respectively, and their values ​​are 3.75 t / hm². 2 4.50t / hm 2 5.25 t / hm 2 6.00t / hm 2 6.75 t / hm 2 Specifically, under the condition of coordinated growth of three ears of grain, the basal nitrogen application rate for low-yield fields is 195 kg / hm². 2 The target yield per hectare will increase by 1.5t, and the nitrogen application rate per hectare will increase by 36kg.

[0019] For medium-yield rice fields, Yn = 195 + (Xn - X1) × 33 / 1.5, where Y is the pure nitrogen application rate (kg / hm2), n represents the value of the "three panicles" synergy level corresponding to the medium-yield field, i.e., values ​​of 1, 2, 3, 4, and 5 for levels I, II, III, IV, and V respectively, and X is the target yield of ratooning rice (kg / hm2). X1, X2, X3, X4, and X5 are the target yields when the "three panicles" synergy level is I, II, III, IV, and V respectively, with values ​​of 5.25 t / hm2. 2 6.00t / hm 2 6.75 t / hm 2 7.50t / hm 2 8.25 t / hm 2 Specifically, for medium-yield fields under the condition of coordinated growth of three ears of grain, the basal nitrogen application rate is 195 kg / hm². 2 The target yield per hectare will increase by 1.5t, and the nitrogen application rate per hectare will increase by 33kg.

[0020] For high-yield fields, Yn = 195 + (Xn - X1) × 30 / 1.5, where Y is the pure nitrogen application rate (kg / hm2), n represents the value of the "three spikes" synergy level corresponding to the high-yield field, i.e., values ​​of 1, 2, 3, 4, and 5 for I, II, III, IV, and V respectively, and X is the target yield of ratooning rice (kg / hm2). 2 X1, X2, X3, X4, and X5 represent the target yields when the three-ear symbiotic relationship is at levels I, II, III, IV, and V, respectively, with values ​​of 6.00 t / hm². 2 6.75 t / hm 2 7.50t / hm 2 8.25 t / hm 2 9.00t / hm 2 Specifically, under the condition of coordinated growth of three ears of grain, the basal nitrogen application rate for high-yield fields is 195 kg / hm². 2 The target yield per hectare will increase by 1.5t, and the nitrogen application rate per hectare will increase by 30kg.

[0021] In this invention, the grading method for the synergy level is based on six indicators: effective panicle number, effective panicle difference, number of grains per panicle, grain difference per panicle, number of days between heading and heading, and actual yield of ratooning rice. In a preferred embodiment of this invention, if four or more of the six indicators (effective panicle number, effective panicle difference, number of grains per panicle, grain difference per panicle, number of days between heading and heading, and actual yield) belong to a certain level, then that synergy level is classified into the corresponding level.

[0022] In this invention, the ratio of nitrogen fertilizer applied three times in the low-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:2:1; the ratio of nitrogen fertilizer applied three times in the medium-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:1:2; and the ratio of nitrogen fertilizer applied three times in the high-yield field is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 1:2:2.

[0023] In this invention, the supporting management technology preferably includes scientifically selecting varieties, early sowing, early transplanting and early harvesting in the first season, moderately increasing the density in the first season, crushing and evenly spreading straw, leaving low stubble, alternating wet and dry irrigation, appropriately delaying harvesting and green pest control.

[0024] In this invention, the scientifically selected varieties are preferably high-yielding rice varieties with strong resistance to rolling, lodging resistance, good overall resistance, and high yield potential. In this invention, the rice varieties include, but are not limited to, one or more of the following: Weiliangyou 8612, Juliangyou 8612, Weiliangyou 2268, Zhenliangyou 8612, Yongyou 4949, Shaoxiang 100, Zhenliangyou Yingxiangsimiao, Chufengyou Yingxiangsimiao, and Heshuangliangyou 138.

[0025] In this invention, the first crop is sown, transplanted, and harvested early. Sowing is preferably done around March 20th, machine transplanting around April 10th, and harvesting around August 5th, reducing the risk of yield reduction due to cold dew winds during the regeneration season.

[0026] In this invention, the density is moderately increased in the first season. The preferred density is 13,000 hills / mu (9 inches × 5 inches) to 17,000 hills / mu (7 inches × 5 inches) to build a sufficient ear population in the first season, laying the foundation for multiple ears in the ratooning season.

[0027] In this invention, the straw is crushed and evenly spread. Preferably, by crushing and evenly spreading (breaking) the straw, the thickness of the straw returned to the field is reduced, and the uniformity of straw return to the field reaches more than 85%, which promotes the rapid germination of axillary buds and seedlings, laying the foundation for a multi-ear population in the regeneration season.

[0028] In this invention, the low stubble height is preferably achieved when harvesting before August 5th, with a stubble height of 10-15cm; or when harvesting after August 5th, with a stubble height of 15-20cm. This promotes the germination of axillary buds at the basal nodes and lays the foundation for a large, uniform panicle population during the regeneration season.

[0029] In this invention, alternating wet and dry irrigation is used. Preferably, 7-10 days before harvest, water is applied to a depth of 3-5 cm, followed by the application of a bud-promoting fertilizer, and then the soil is allowed to dry naturally. 3-5 days after harvest, once the regrowth buds have emerged, water is applied to a depth of 3-5 cm, followed by the application of a seedling-promoting fertilizer, and then the soil is allowed to dry naturally to avoid scalding the buds with high temperatures. Before heading, the soil is kept moist by applying a quick, light irrigation; during the heading stage, water is applied to a depth of 3-5 cm; and during the grain-filling to maturity stage, the soil is kept moist by applying a quick, light irrigation.

[0030] In this invention, the harvest is delayed by 3-5 days, preferably around October 25th, to improve the uniformity of maturity between compacted and uncompacted rows, reduce the green grain rate, and improve appearance, processing quality, and taste quality.

[0031] In this invention, green pest control is employed. Preferably, following the principle of "prevention first, combined with control," the focus is on controlling rice stem borers and rice planthoppers in the first and second harvest seasons to ensure the health of the first harvest rice stubble, thus facilitating the formation of a large, uniform panicle population. In one preferred embodiment, rice stem borer control uses 25% spinosad water-dispersible granules at a dosage of 10-15 g / mu (approximately 0.067 hectares), diluted with 20-50 L / mu for manual application and 1-5 L / mu for drone application. In another preferred embodiment, rice planthopper control uses 10% trifluralin at a dosage of 15-20 ml / mu (approximately 0.067 hectares), diluted with 20-50 L / mu for manual application and 1-5 L / mu for drone application.

[0032] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0033] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available products.

[0034] Example 1: Verification of the effect of controlled nitrogen application in fields with different soil fertility This embodiment aims to verify the effects of the controlled nitrogen application calculation formula and fertilization ratio proposed in this invention on the synergistic effect of the three panicles on rice paddies during the regeneration season and on yield under different soil fertility levels. 1. Experimental Design Test sites: Meihua Village, Xidu Town, Hengyang County, Hunan Province; Yanwuzhou Village, Beisheng Town, Liuyang City, Hunan Province Experimental variety: Weiliangyou 8612.

[0035] Experimental plots: Five low-yield, five medium-yield, and five high-yield plots were selected from the same area with uniform soil fertility. Soil fertility level was determined based on soil fertility, annual yield, and the indicators in Table 1.

[0036] Table 1. Synergistic Grading Method of "Three Ears"

[0037] Experimental treatments: Five treatments were set up in each field, corresponding to the target "three ears" synergistic level from I to V, and the nitrogen application rate and fertilizer ratio were calculated according to the formula of this invention.

[0038] Treatment of low-yield farmland: The target yields (Xn) are set at 3.75 t / hm², 4.50 t / hm², 5.25 t / hm², 6.00 t / hm 2 , 6.75 t / hm² respectively. According to the formula Yn = 195 + (Xn - 3.75) × 36 / 1.5, the calculated pure nitrogen application rates are 195 kg / hm 2 , 213 kg / hm², 231 kg / hm², 249 kg / hm², 267 kg / hm² respectively. Nitrogen fertilizer is applied in three times according to the ratio of pre-bud fertilizer: seedling-promoting fertilizer: ear fertilizer = 2:2:1.

[0039] Treatment of medium-yield farmland: The target yields (Xn) are set at 5.25 t / hm², 6.00 t / hm², 6.75 t / hm², 7.50 t / hm 2 , 8.25 t / hm² respectively. According to the formula Yn = 195 + (Xn - 5.25) × 33 / 1.5, the calculated pure nitrogen application rates are 195 kg / hm², 211.5 kg / hm², 228 kg / hm², 244.5 kg / hm², 261 kg / hm² respectively. Nitrogen fertilizer is applied in three times according to the ratio of pre-bud fertilizer: seedling-promoting fertilizer: ear fertilizer = 2:1:2.

[0040] Treatment of high-yield farmland: The target yields (Xn) are set at 6.00 t / hm², 6.75 t / hm², 7.50 t / hm², 8.25 t / hm 2 , 9.00 t / hm² respectively. According to the formula Yn = 195 + (Xn - 6.00) × 30 / 1.5, the calculated pure nitrogen application rates are 195 kg / hm², 210 kg / hm², 225 kg / hm², 240 kg / hm², 255 kg / hm² respectively. Nitrogen fertilizer is applied in three times according to the ratio of pre-bud fertilizer: seedling-promoting fertilizer: ear fertilizer = 1:2:2.

[0041] All treatments uniformly adopt the supporting technologies of the present invention, and the supporting cultivation management measures are as follows: (1) Early sowing, early transplanting and early harvesting in the first season. Sow around March 20, transplant by machine around April 10, and harvest around August 5 to reduce the risk of yield reduction caused by cold dew wind in the ratooning season.

[0042] (2) Appropriately increase the planting density in the first season. The density ranges from 13,000 holes / mu (9 inches × 5 inches) to 17,000 holes / mu (7 inches × 5 inches), and a sufficient panicle population in the first season is constructed to lay a foundation for achieving more panicles in the ratooning season.

[0043] (3) Uniformly spread the crushed straw. By uniformly spreading the crushed straw, the thickness of straw returning to the field is reduced, and the uniformity of straw returning to the field reaches more than 85%, promoting the rapid germination of axillary buds into seedlings and laying a foundation for a multi-panicle population in the ratooning season.

[0044] (4) Leave a low stubble. If harvested before August 5, leave a stubble height of 10-15cm; if harvested after August 5, leave a stubble height of 15-20cm to promote the germination of axillary buds at the basal nodes and lay the foundation for a large and uniform panicle population in the regeneration season.

[0045] (5) Alternating wet and dry irrigation. 7-10 days before harvest, irrigate to a depth of 3-5 cm, apply fertilizer to promote bud growth, and then let it dry naturally; 3-5 days after harvest, when the buds have sprouted, irrigate to a depth of 3-5 cm, apply fertilizer to promote seedling growth, and then let it dry naturally to avoid high temperature scalding of the buds; before heading, irrigate with running water to keep the soil moist, during the heading period, irrigate to a depth of 3-5 cm, and during the grain filling to maturity period, irrigate with running water to keep the soil moist.

[0046] (6) Delay the harvest appropriately. Delay the harvest by 3-5 days, harvesting around October 25th, to improve the uniformity of maturity between compacted and uncompacted rows, reduce the green grain rate, and improve appearance, processing quality and taste quality.

[0047] (7) Green pest control. In accordance with the principle of "prevention first and control combined", we will focus on strengthening the control of rice stem borer (12g / mu of 25% spinosad water-dispersible granules, 30L / mu for manual application and 2L / mu for drone application) and rice planthopper (18ml / mu of 10% trifluralin, 30L / mu for manual application and 2L / mu for drone application) in the first and second seasons to ensure the health of rice stubble in the first season, so as to facilitate the construction of a multi-panicle, large-panicle, uniform-panicle population.

[0048] 2. Results and Analysis During the ripening period of the regeneration season, the synergistic indicators of the three ears and the yield of each treatment were investigated, and the results are shown in Table 2.

[0049] Table 2. Synergistic effect of the three spikelets and yield of Weiliangyou 8612 under controlled nitrogen application (data are average values)

[0050] Note: All data above are averages. The effective ear difference is the number of ears per unit area in non-compacted rows minus the effective ear number per unit area in compacted rows. The grain difference per ear is the number of grains per ear in compacted rows minus the number of grains per ear in non-compacted rows. The number of days between the beginning of heading is the number of days in the heading period of compacted rows minus the number of days in the heading period of non-compacted rows. The effective ear number refers to the number of ears with 5 or more grains per ear per square meter. Results Table 2 and Figure 2 The results showed that with the increase of nitrogen application rate and target yield, the synergistic level of the three ears (ears, spikelets, and panicles) in low-yield, medium-yield, and high-yield fields could all be improved from level I to level V. Specifically: Effective number of ears and ear uniformity: The effective number of ears increased significantly in all three types of fields, and the effective ear difference (the difference in the number of ears between un-compacted rows and compacted rows) continued to decrease, indicating that the ear uniformity between compacted rows and un-compacted rows was greatly improved.

[0051] Ear type and ear type uniformity: The number of grains per ear steadily increased, while the difference in the number of grains per ear (i.e. the difference in the number of effective ears per unit area between non-compacted rows and compacted rows) decreased significantly, indicating that the ear type increased and became more uniform.

[0052] Synchronicity of reproductive progress: The shortening of the interval between the first heading of grains indicates that the reproductive progress of compacted and uncompacted rows tends to be synchronized.

[0053] Yield: Actual yield closely matches target yield. Low-yield, medium-yield, and high-yield fields were upgraded from Level I to Level V, with nitrogen application rates increasing by 72 kg / hm², 66 kg / hm², and 60 kg / hm² respectively. Actual yields increased by 2.95 t / hm², 3.05 t / hm², and 3.11 t / hm² respectively, demonstrating significant yield increases.

[0054] This embodiment confirms that the controlled nitrogen application method provided by the present invention can precisely regulate the amount and strategy of nitrogen fertilizer application according to soil fertility level and target yield, effectively promoting the synergistic formation of "multiple panicles, large panicles, and uniform panicles" in the ratooning season. It is a key technology for achieving high and stable yields of ratooning rice. The rice growth of the ratooning rice three-panicle synergistic high-yield cultivation method of the present invention is shown in the figure. Figure 1 .

[0055] Comparative Example 1 The traditional method for cultivating ratooning rice includes the following steps: harvesting the first crop using a combine harvester without a straw crushing and spreading device, leaving a high stubble (over 40cm); immediately irrigating after the first harvest; and applying urea at 300 kg / hm². 2 (pure N 138 kg / hm) 2 The ratio of bud-promoting fertilizer to seedling-enhancing fertilizer to panicle-growing fertilizer is 1:1:0 or 0:2:0 respectively. Under the traditional model, the yield in the ratoon season is 6.0 t / hm². 2 The average is 3.6 t / hm. 2 See below for rice growth information. Figure 2 .

[0056] Example 2 This embodiment uses a medium-yield field as an example to illustrate the complete operation process of the present invention in detail.

[0057] 1. Fields and Varieties Choose a field with moderate soil fertility. Select the variety "Wei Liang You 8612", which is resistant to compaction, lodging, and has strong regeneration ability.

[0058] 2. First Quarter Management Sowing and transplanting: Sowing was carried out on March 15th, and seedlings were raised by machine transplanting. Transplanting was carried out on April 8th using a high-speed rice transplanter, with a planting density of 16,700 hills / acre (row spacing of 9 inches × 4 inches).

[0059] Water and pest management: Follow the local high-yield cultivation model.

[0060] 3. Regeneration Season Management First Harvest: The first crop of rice was harvested on August 5th using a combine harvester. At harvest, the stubble height was controlled at 15cm. Simultaneously, the straw was shredded and evenly spread across the field, ensuring a spreading uniformity of over 85%.

[0061] Apply fertilizer to promote bud growth: Nine days before harvest (July 27), irrigate the field to a depth of 3-5 cm, and apply 6.4 kg of fertilizer per mu (i.e., about 13.9 kg of urea per mu, or other nitrogen fertilizers of equal nitrogen content) based on pure nitrogen. Then let the water drain naturally.

[0062] Apply seedling fertilizer: Four days after harvest (August 9), when the regenerated buds have sprouted, irrigate the field to a depth of 3-5 cm and apply 3.2 kg of seedling fertilizer per mu (i.e., about 7.0 kg of urea per mu, or other nitrogen fertilizers of equal nitrogen content) based on pure nitrogen. Then let the water drain naturally.

[0063] Applying top dressing fertilizer: 18 days after harvest (August 23), irrigate the field to a depth of 3-5 cm, and apply 6.4 kg of top dressing fertilizer per mu (i.e., about 13.9 kg of urea per mu, or other nitrogen fertilizers of equal nitrogen amount) based on pure nitrogen. Then let the water drain naturally.

[0064] Water management: After applying seedling and heading fertilizers, until heading, the field adopts an alternating dry and wet irrigation pattern of "rushing water, letting it dry naturally, and maintaining a moist environment." Maintain a water layer of 3-5 cm during the heading stage. From grain filling to maturity, use alternating dry and wet irrigation again to maintain root vitality.

[0065] Total nitrogen application rate calculation: 6.4 + 3.2 + 6.4 = 16 kg of pure nitrogen per mu (667 square meters), equivalent to 240 kg / hm². This corresponds to the recommended nitrogen application rate for a target yield of 7.50 t / hm² (Grade IV) in medium-yield fields.

[0066] Pest control: During the regeneration season, focus on monitoring rice stem borers and rice planthoppers. Use 12g / mu of 25% spinosad water-dispersible granules (drone spraying, diluted with 2L of water) to control rice stem borers; use 18ml / mu of 10% trifluralin (drone spraying, diluted with 2L of water) to control rice planthoppers.

[0067] Harvest: Harvest was delayed by 4 days compared to the normal maturity period, and mechanical harvesting was carried out on October 24.

[0068] 4. Effects Post-harvest yield measurement and crop evaluation results showed that: The field achieved 422.5 effective panicles / m² during the ratooning season, with an effective panicle difference of 56.4 panicles / m². Each panicle had 89.2 grains, with a grain difference of 6.4 grains per panicle, a seed setting rate of 82.2%, and a thousand-grain weight of 25.5 g. The interval between the beginning and end of the heading stage was 6 days. The actual yield reached 7.78 t / hm². 2 .

[0069] Of the above six indicators, more than four fall within the "Level IV" standard range for producing fields in Table 1. Therefore, the "three ears" synergistic grade is rated as Level IV. The actual yield is highly consistent with the Level IV target yield. Furthermore, the compacted and uncompacted rows grow evenly, and the green grain rate is low, thus achieving high and stable yield.

[0070] This embodiment demonstrates that integrating the controlled nitrogen application formula, fertilization structure, and supporting agronomic measures of the present invention can effectively solve the problem of yield reduction due to crushing during machine-harvested ratooning rice. It is highly operable, has a significant yield-increasing effect, and is suitable for large-scale promotion and application.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for high-yield cultivation of three panicles in ratooning rice, characterized in that, Includes the following steps: Calculate the nitrogen application rate based on soil fertility level and target yield; apply nitrogen fertilizer in three proportions: bud-promoting fertilizer, seedling-enhancing fertilizer, and ear-growing fertilizer. Supporting measures include variety selection, early sowing, early transplanting and early harvesting, reasonable dense planting, even distribution of straw, low stubble retention, alternating wet and dry irrigation, delayed harvesting and pest control. The soil fertility level is divided into low-yield, medium-yield, and high-yield fields; the nitrogen application rate calculation formulas are as follows: low-yield field: Yn=195+(Xn-X1)×36 / 1.5; medium-yield field: Yn=195+(Xn-X1)×33 / 1.5; high-yield field: Yn=195+(Xn-X1)×30 / 1.5; n is the value of the synergy level corresponding to the soil fertility level; the synergy level is divided into I, II, III, IV, and V, with corresponding values ​​of 1, 2, 3, 4, and 5; X is the target yield of ratooning rice for the soil fertility level; X1, X2, X3, X4, and X5 are the target yields for synergy levels I, II, III, IV, and V, respectively.

2. The cultivation method according to claim 1, characterized in that, The grading method for the synergistic level is based on six indicators: effective panicle number, effective panicle difference, number of grains per panicle, grain difference per panicle, number of days between the beginning of heading and actual yield of rice in the ratoon season.

3. The cultivation method according to claim 1, characterized in that, The ratio of nitrogen fertilizer applied three times to low-yield fields is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:2:1; the ratio of nitrogen fertilizer applied three times to medium-yield fields is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 2:1:2; and the ratio of nitrogen fertilizer applied three times to high-yield fields is bud-promoting fertilizer: seedling-promoting fertilizer: ear-heading fertilizer = 1:2:

2.

4. The cultivation method according to claim 1, characterized in that, The variety in question is a rice variety that is resistant to crushing and lodging.

5. The cultivation method according to claim 4, characterized in that, The rice varieties include one or more of the following: Weiliangyou 8612, Juliangyou 8612, Weiliangyou 2268, Zhenliangyou 8612, Yongyou 4949, Shaoxiang 100, Zhenliangyou Yingxiangsimiao, Chufengyou Yingxiangsimiao, and Heshuangliangyou 138.

6. The cultivation method according to claim 1, characterized in that, The recommended density for close planting is 13,000 holes / acre to 17,000 holes / acre.

7. The cultivation method according to claim 1, characterized in that, The stubble height is 10-20cm.

8. The cultivation method according to claim 1, characterized in that, The alternating wet and dry irrigation includes irrigating with water to a depth of 3-5 cm 7-10 days before harvesting, applying fertilizer to promote bud growth, and waiting for the water to dry naturally; and irrigating with water to a depth of 3-5 cm 3-5 days after harvesting, after the regrowth of buds, applying fertilizer to promote seedling growth, and waiting for the water to dry naturally.

9. The cultivation method according to claim 1, characterized in that, The uniformity of straw return to the field after uniform straw distribution is over 85%.

10. The cultivation method according to claim 1, characterized in that, The pest control measures include strengthening the control of rice stem borers and rice planthoppers in the first and second cropping seasons.

Images