CN113424675A

CN113424675A - Method for returning rice straw to field by water raking slurry in autumn

Info

Publication number: CN113424675A
Application number: CN202110579018.1A
Authority: CN
Inventors: 赫兵; 严永峰; 李超; 陈殿元; 武志海; 王帅; 党姝; 耿艳秋; 刘明; 包岩; 邢旭; 刘昌辉
Original assignee: Jilin Agricultural Science and Technology College
Current assignee: Jilin Agricultural Science and Technology College
Priority date: 2021-05-26
Filing date: 2021-05-26
Publication date: 2021-09-24

Abstract

The invention discloses a method for returning rice straws to fields by water raking slurry in autumn, which relates to the technical field of agricultural production soil preparation, and comprises the following steps: harvesting and crushing rice straws after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in a field; irrigating and soaking the field for 3-5 days; carrying out rotary tillage operation, and mixing the rice straws and the slurry. The method of the invention is used for returning the straws to the field, can ensure that the rice straws are fully decomposed, effectively solves the problem that the straws compete for nitrogen with the rice in the rotting process after rice transplanting, reduces the generation of methane gas, and leads the rice production to be carried out smoothly. And the idle period of people is utilized, and the cost of straw treatment is reduced.

Description

Method for returning rice straw to field by water raking slurry in autumn

Technical Field

The invention relates to the technical field of agricultural production soil preparation, in particular to a method for returning rice straws to fields in autumn by water raking slurry.

Background

According to the survey of the Chinese statistical yearbook (2020): the rice straw yield in China is 1.7 hundred million tons, and the straw resources are very rich. The straw treatment in China is relatively laggard, particularly the overall level of direct straw returning is low, and the direct straw returning rate is only 17.6 percent on average. The limiting factor for limiting the returning of the rice straws to the field is mainly that the cost of the traditional stacking fermentation returning is high; the straw harrowing and returning to the field are directly carried out in spring, the temperature is low, the straw decomposition period is short, and simultaneously, a large amount of gas such as methane is generated, so that the tillering of rice is influenced, the agricultural production cannot be normally carried out or the yield is easily reduced when the technical measures of cultivation and management are not proper. To solve the problem, the decomposition period of the rice straw should be prolonged to the maximum extent and the water should be supplemented. Therefore, after the rice is harvested in autumn, the rice straws are buried into the slurry by a rotary cultivator after being irrigated and soaked in the field before being frozen on a plough layer, so that the rice straws are fully decomposed, and the rice production is smoothly carried out.

Disclosure of Invention

The invention aims to provide a method for harrowing and returning rice straws to fields in autumn, which is characterized in that after rice is harvested in autumn, water is poured into a plough layer before being frozen, and the straws are buried into slurry by a rotary cultivator after being soaked in the field, so that the rice straws are fully decomposed, and the rice production is smoothly carried out.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method for returning rice straws to fields by water raking slurry in autumn is characterized by comprising the following steps:

(1) harvesting and crushing rice straws after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in a field;

(2) irrigating and soaking the field for 3-5 days, and softening the soil layer;

(3) carrying out rotary tillage operation, and mixing the rice straws and the slurry.

Further, the harvesting, crushing and spreading in the step (1) are specifically carried out, wherein the height of the harvested stubble is less than or equal to 20cm, the length of the crushed rice straw is less than or equal to 10cm, and the thickness of the rice straw spread in the field is less than or equal to 10 cm.

The stubble height is less than or equal to 20cm, which is beneficial to the complete burying under the mud during the rotary tillage.

The excessive or uneven returning amount of the rice straws is easy to cause contradiction between microorganisms and crops for competing for soil nutrients, and even phenomena of yellow seedlings, dead seedlings, yield reduction and the like occur.

Furthermore, the soil layer which is more than 5cm after irrigation and field soaking in the step (2) becomes soft, so that rice straws and slurry are mixed during rotary tillage, and the phenomenon that the soil is too loose, the pore size proportion is not uniform, and large pores are too large to cause wind leakage after the straws are turned over and returned to the field is avoided, so that the soil is not in close contact with seeds and can not normally sprout.

Further, the step (1) adopts a combine harvester to harvest, crush and spread rice straws.

Further, in the rotary tillage in the step (3), an obvious water layer is not kept in the field before the rotary tillage, so that more than 80% of the soil surface of the paddy field cannot be seen, the straws are prevented from floating, and the harrowing and the grass pressing are not facilitated.

Further, the rotary tillage in the step (3) is carried out at intervals of one working width, and the specific working method is implemented as follows:

(1) 1 operation width is given from the ground, and rotary tillage is started;

(2) when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths;

(3) when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width;

(4) when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths;

(5) and finally, carrying out rotary tillage on the periphery of the land.

The rotary tillage is carried out at an interval of one operation width, so that the movement of soil can be reduced, the straw is prevented from being piled up and wound to influence the rotary tillage, and the ground can be kept smooth after the rotary tillage.

And (3) further, carrying out rotary tillage in the step (3), wherein the rotary tillage depth is more than 20cm, the rotary tillage depth is equal to or less than 4cm until the ground is flat, and the rice straws are completely mixed in the slurry.

If the field surface is uneven, the phenomena of uneven growth, uneven seedling emergence and the like of crops are easily caused.

The invention has the beneficial effects that:

rice straw raking and pulp returning operation is carried out after the rice is harvested in autumn and before the plough layer is frozen, and compared with the conventional rice straw raking and pulp returning operation which turns over and returns to the field in autumn, the rice straw decomposition is accelerated by the autumn raking and pulp returning operation; the time from before freezing of the plough layer in winter to before transplanting rice seedlings is effectively utilized for full decomposition, and the problem that the straw continuously decays to compete with the rice for nitrogen after the rice straw is decayed in the early stage and is insufficiently transplanted is solved; the conditions that the normal production of rice is influenced and a large amount of harmful gas such as methane and the like is generated to influence the normal growth of rice plants due to the short frost-free period in spring and the low decomposition degree after the straws are returned to the field are avoided. Meanwhile, the idle period of people is utilized, and the straw treatment cost is reduced. The autumn harrow returning to the field can also increase the rice yield and fertility; the occurrence of diseases, insect pests and weeds is inhibited to a certain extent, because the water raking slurry returning to the field in autumn destroys the overwintering living environment of various fungal soil spread diseases, overwintering pupas, aged larvae, annual grass seeds and perennial roots in paddy fields and the like, the rice straws lose germination and reproductive capacity, and meanwhile, the rice straws are raked into mud to return to the field, and the purposes of weed killing, insect prevention, disease control and soil fertility betterment are achieved in a physical mode by utilizing freezing damage, so that the sustainable development of the rice industry is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a path before a swing of one working width;

FIG. 2 is a schematic diagram of a route after a swing of one working width;

FIG. 3 is a schematic view of the path around the rotary tillage land;

FIG. 4 shows CH with different processing modes₄Total amount of emissions;

FIG. 5 shows the variation of ORP in soil in different months;

FIG. 6 shows different processes CH₄Emissions are related to ORP (. about.5% level is intentionally different);

FIG. 7 shows the change of the weight loss rate of rice straw;

FIG. 8 shows the variation of the breaking tension of rice straw;

FIG. 9 is a comparison of the rotting degree of the straws in different returning modes;

fig. 10 shows the variation of the characteristics of the different treatments during each growth period.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The rice combine harvester used in the following examples is a full (half) feed type combine harvester equipped with a straw crushing device and a straw spreader, and the safety technical requirements meet the requirements of GB 16151.2. The rotary cultivator selects a common paddy field rotary cultivator or a special harrow/pulper for returning straws to the field, and is matched with a tractor with corresponding power. The safety technical requirements of the rotary cultivator are required to meet the GB/T5668 regulations. The safety technical requirements of the tractor meet the GB16151.1 regulations. The rice seeds are selected from varieties approved by the country or the region, and the seed quality is in accordance with the GB 4404.1. The fertilizer should meet the NY/T496 regulations. The operation requirement of mechanical harvest is in accordance with NY/T498.

A method for returning rice straws to fields by water raking slurry in autumn comprises the following steps:

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is less than or equal to 20cm, the length of the crushed rice straw is less than or equal to 10cm, and the thickness of the rice straw spread in the field is less than or equal to 10 cm.

(2) Irrigating and soaking the field for 3-5 days until a soil layer with the thickness of more than 5cm becomes soft;

(3) and (4) carrying out rotary tillage operation, wherein an obvious water layer is not kept in the field before rotary tillage, so that more than 80% of soil surface of a paddy field cannot be seen. The rotary tillage time is separated by one operation width, and the specific operation method is implemented as follows:

1 operation width is given from the ground, and rotary tillage is started; when the distance between the ground edge and the ground edge is one working width, the rotation is carried out, and the rotating width is two working widths (figure 1); when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance between the ground edge and the ground edge is one working width, the rotation is carried out, and the rotating width is two working widths (figure 2); finally, the rotary tillage around the land is carried out (figure 3). The rotary tillage depth is more than 20cm, the ground is smooth, the height difference is less than or equal to 4cm, and the rice straws are completely mixed in the slurry.

Soil preparation in spring of next year: and (5) harrowing with ultra-shallow water after soaking the field for 2-3 d. On the premise of ensuring the quality of rice transplanting, the slurry is not too deep, and the depth is preferably 5-10 cm. Depositing for 2-3 days and transplanting.

And (3) fertilizer and water management: fertilizing 150-175 kg of nitrogen fertilizer (N) and P fertilizer (P) per hectare in the whole growth period₂O₅) 30-45 kg of potash fertilizer (K)₂O)30 to 45 kilograms.

And (3) fertilizer amount distribution: before harrowing, 45 percent of nitrogenous fertilizer, 100 percent of phosphate fertilizer and 50 percent of potash fertilizer are applied as base fertilizers at one time. The tiller fertilizer is 30% of the topdressing nitrogen fertilizer when the leaves of the rice are 3.5-4.5. The ear fertilizer is 25 percent of the additional nitrogen fertilizer and 50 percent of the potassium fertilizer in the initial stage of ear differentiation (pouring 3 leaves).

Water content management: and keeping a 3-5 cm shallow water layer after seedling transplanting until a tillering stage. And starting shallow-wet-dry water layer management until the jointing stage is completed, wherein the former water is not found and the latter water is not found. The water is removed 30 days after the harvest, and premature water removal is easy to cause premature senility.

Mechanical harvesting: harvesting is carried out when more than 90% of rice grains turn yellow after being mature or one third of cob turns yellow.

Example 1

A method for returning rice straws to fields in autumn by water raking slurry in Yilaxi in Yongji county of Jilin city, Jilin province comprises the following steps:

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is 19cm, the length of the crushed rice straw is 9cm, and the thickness of the rice straw spread in the field is 9 cm.

(2) Irrigating and soaking the field for 4 days until a soil layer of 8cm becomes soft;

(3) and (4) carrying out rotary tillage operation, wherein an obvious water layer is not kept in the field before rotary tillage, so that 80% of soil surface of a paddy field cannot be seen. The rotary tillage time is separated by one operation width, and the specific operation method is implemented as follows:

1 operation width is given from the ground, and rotary tillage is started; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; and finally, carrying out rotary tillage on the periphery of the land. The rotary tillage depth is 22cm, the maximum height difference is 4cm when the ground is flat, and the rice straws are completely mixed in the slurry.

Soil preparation in spring of next year: raking with ultra-shallow water after steeping for 3 d. And stirring the rice seedlings under the premise of ensuring the quality of the rice seedlings, wherein the stirring depth is 8 cm. And (5) transplanting after 2d of precipitation (under the same implementation condition, selecting a Jihong 9 rice variety and a Jinong 853 rice variety to transplant in different areas respectively).

And (3) fertilizer and water management: the fertilizer is applied to each hectare in the whole growth period, 165 kilograms of nitrogen fertilizer (N) and 165 kilograms of phosphate fertilizer (P)₂O₅)38 kg of potash fertilizer (K)₂O)38 kg.

And (3) fertilizer amount distribution: before harrowing, 45 percent of nitrogenous fertilizer, 100 percent of phosphate fertilizer and 50 percent of potash fertilizer are applied as base fertilizers at one time. The tiller fertilizer is 30% of the additional nitrogen fertilizer when 4 leaves of rice are fertilized. The ear fertilizer is 25 percent of the additional nitrogen fertilizer and 50 percent of the potassium fertilizer in the initial stage of ear differentiation (pouring 3 leaves).

Water content management: and keeping a 4cm shallow water layer after seedling transplanting until tillering stage. And starting shallow-wet-dry water layer management until the jointing stage is completed, wherein the former water is not found and the latter water is not found. And removing water after harvesting and trimming the ears for 30 days.

Mechanical harvesting: harvesting is performed when 90% of the grains turn yellow when they are mature, or one third of the cob turns yellow.

Example 2

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is 15cm, the length of the crushed rice straw is 8cm, and the thickness of the rice straw spread in the field is 8 cm.

(2) Irrigating and soaking the field for 3 days until a soil layer of 5cm becomes soft;

(3) and (4) carrying out rotary tillage operation, wherein an obvious water layer is not kept in the field before rotary tillage, so that 85% of soil surface of the paddy field cannot be seen. The rotary tillage time is separated by one operation width, and the specific operation method is implemented as follows:

1 operation width is given from the ground, and rotary tillage is started; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; and finally, carrying out rotary tillage on the periphery of the land. The rotary tillage depth is 25cm, the maximum height difference is 3cm when the ground is flat, and the rice straws are completely mixed in the slurry.

Soil preparation in spring of next year: raking with ultra-shallow water after steeping for 3 d. And stirring the rice seedlings under the premise of ensuring the quality of the rice seedlings, wherein the stirring depth is 8 cm. And depositing for 2d and transplanting rice seedlings.

Example 3

A method for carrying out rice straw autumn water raking and pulp returning in nine areas of Changchun city in Jilin province comprises the following steps:

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is 20cm, the length of the crushed rice straw is 10cm, and the thickness of the rice straw spread in the field is 10 cm.

1 operation width is given from the ground, and rotary tillage is started; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; and finally, carrying out rotary tillage on the periphery of the land. The rotary tillage depth is 20cm, the maximum height difference is 4cm when the ground is flat, and the rice straws are completely mixed in the slurry.

Example 4

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is 16cm, the length of the crushed rice straw is 7cm, and the thickness of the rice straw spread in the field is 7 cm.

(2) Irrigating and soaking the field for 5 days until a soil layer of 7cm becomes soft;

1 operation width is given from the ground, and rotary tillage is started; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; and finally, carrying out rotary tillage on the periphery of the land. The rotary tillage depth is 25cm, the maximum height difference is 3.5cm when the ground is flat, and the rice straws are completely mixed in the slurry.

Example 5

A method for returning rice straws to fields in autumn by water raking slurry in Wangchang county, Yongji City, Jilin province comprises the following steps:

(1) harvesting and crushing rice straws by using a combine harvester after harvesting rice in autumn and before freezing a plough layer, and uniformly spreading the crushed rice straws in the field. The height of the harvested stubble is 17cm, the length of the crushed rice straw is 9.5cm, and the thickness of the rice straw spread in the field is 9.5 cm.

1 operation width is given from the ground, and rotary tillage is started; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; when the rotary tillage reaches two operation widths away from the ground head at the other side, carrying out the convolution operation with one convolution width as one operation width; when the distance from the ground edge is one operation width, the rotation is carried out, and the rotation width is two operation widths; and finally, carrying out rotary tillage on the periphery of the land. The rotary tillage depth is 23cm, the maximum height difference is 3cm when the ground is flat, and the rice straws are completely mixed in the slurry.

Comparative example 1 differs from example 1 in that water raking of rice straw to field (hereinafter described as field-not-applied region) is not performed;

comparative example 2 is different from example 1 in that the water raking of rice straw and returning to field is performed in spring (hereinafter, described as spring returning).

Comparing the data obtained in example 1 (hereinafter described as autumn field application) with the data obtained in comparative example 1 (field application free zone), comparative example 2 (spring field application) gave the following results:

firstly, evaluating the technical effect of rice straw autumn water raking and pulp returning:

1. rice field CH for paddy rice straw autumn water raking and pulp returning₄Effect of emission dynamics

By comparing CH in different treatment modes₄The discharge amount can be found to reach CH in 8 months compared with the area without returning field₄CH with peak discharge, spring return and autumn return₄The emission amount reaches the peak in 6 months. Wherein the spring is returned to the field in the 6-month CH₄The proportion of the discharged amount in the total amount of the discharged amount is 46.01 percent, and the percentage of the discharged amount in returning to the field in autumn is 44.78 percent. But returning to the field in different months in autumn than in spring₄The occurrence was more average and more than 10.80% of the total emission had been CH since 5 months₄And discharged (table 1). From CH₄In terms of total discharge, there is no returning area CH₄The total discharge amount is 54.77mg/m²The spring return to field is 181.33mg/m²The amount of the fertilizer returned to the field in autumn is 86.74mg/m². Returning to field CH in autumn₄The total amount of discharge is approximately one-half of the amount returned to the field in spring (fig. 4).

TABLE 1 different months CH₄Discharge situation

2. Influence of autumn water harrowing and slurry returning of rice straw on dynamic state of ORP (oxidation reduction potential) of rice field soil

The soil ORP in different treatment months shows negative value in the whole growth period and decreases after 5 months of paddy field irrigation. Wherein the change of spring and autumn returning ORP and CH₄The emission peak is different in 6 months, and both reach the lowest in 7 monthsThe peak value is-304 mv for spring return and-277 mv for autumn return, and the strong reduction state is presented. The area without returning field reaches the peak value of-223 mv in the middle 8 months. Compared to the two treatment modes of returning to the field, the zone without returning to the field is delayed and reduced in terms of the month and intensity of ORP peak occurrence. While the ORP values of autumn returning to field were relatively high throughout the growth period, i.e. exhibited a weaker reduction state, compared to spring returning to field (fig. 5).

3. Dynamic soil ORP and CH in autumn water harrowing returning of rice straw₄Relationship between discharge amount

Different processing of CH₄The discharge amount and the ORP show a negative correlation, and an intentional correlation exists between the discharge amount and the ORP under the conditions of no returning area and spring returning. I.e. CH as ORP number increases₄The less the amount of discharge. That is, the greater the extent of reduced state of the rice field is, CH₄The higher the amount of emissions and vice versa (fig. 6).

Then we use CH separately₄In response to the emissions, a model fitting of a standard least squares method was performed with the ORP value as a variable. The following different processed CH are obtained₄Emission and ORP values:

no field returning area: CH (CH)₄Emission-2.5338-0.04730 XORP

Returning to the field in spring: CH (CH)₄Emission-3.4040-0.07564 XORP

Returning to fields in autumn: CH (CH)₄Emission-0.2362-0.04315 XORP

Calculated from these relationships, when CH₄When the discharge amount is equal to 0, the ORP of the non-returning area is-53.57 mv, the ORP of the returning area in spring is-45.00 mv, and the ORP of the returning area in autumn is-5.47 mv, namely the ORP can be regarded as CH₄Critical ORP value of emissions. Therefore, compared with the spring returning and non-returning areas, the water harrowing is carried out on the straw returning in autumn immediately after the straw returning in autumn, the ORP value of the rice field can be reduced to a negative value, and CH begins to be discharged₄. And CH₄The earlier CH is discharged under the condition that the total discharge amount, namely the total amount of the organic matters returned to the field is constant₄Can reduce CH₄High peak value of emission, and reduction of extreme reduction of rice plantsAnd (4) sexual hazard.

4. Influence of autumn water-raking-slurry returning technology of rice straws on straw weight loss rate and breaking tension

Compared with returning to the field in spring, the weight loss rate of the rice straws returned to the field in autumn is higher in the whole growth period. And returning to the field in autumn for the first 5 months of the survey, the rice straw has begun to lose weight compared to the initial mass. It was demonstrated that after the autumn harrow was returned to the field, the straws were effectively decomposed during the period before the spring of the next year was transplanted (fig. 7). The breaking tension of the straw returned to the field in autumn is smaller than that of the straw returned to the field in spring in the whole growth period. However, the breaking tension of the field returned to the field at a later stage, particularly in the spring after 6 months, is reduced to a greater extent, and it is expected that the breaking tension of the field will eventually approach the same level if the decay time is prolonged (fig. 8).

Second, the influence of autumn water-harrowing and field-returning technology of rice straw on soil property

Compared with the method before returning to the field (soil is taken in autumn), the effective phosphorus, the quick-acting potassium and the organic matters after returning to the field under different treatment conditions (soil is taken in autumn in the next year) are all improved. The alkali-hydrolyzed nitrogen in the spring and autumn returning fields is reduced compared with that before returning, and the degree of reduction in the autumn returning field is larger than that in the spring returning field, which is presumed to be caused by the rotten and mature consumption of the straws. The pH value of the soil after returning to the field in autumn is reduced compared with that before returning to the field. The difference between the values of exchangeable calcium and magnesium in each treatment zone after and before returning to the field was not great (Table 2).

TABLE 2 variation of soil Properties for different treatments

Influence of autumn water raking and pulp returning technology of rice straws on rice growth characteristics

The plant heights of different treatments are changed from high to low in the whole growth period in the following sequence: returning to fields in autumn, returning to fields in spring and no returning to fields areas. The leaf color of the spring returning field and the autumn returning field is higher than that of the non-returning field, and the decline degree in the later growth period is lower. The final leaf color was highest at 30.2 for autumn return, next 29.3 for spring return, and lowest at 25.9 for no return. The tillering number of different treatments reaches the peak in the last 7 months, but the tillering number of the autumn returning field is slowly reduced, and the final tillering number is 24.6. The tillering number of the returned field in spring is slightly reduced after reaching the peak, and then slightly increased in the last 8 months, and finally the tillering number is 23.7. The tillering number of the area without returning to the field is obviously reduced in the later period of growth, and the final tillering number is 21.3 (figure 10).

Influence of autumn water-raking-slurry returning technology of rice straws on yield and yield constituent elements

Compared with the region without returning field, the region is returned to the field in spring and autumn by 1m²The spike number is obviously improved, and the spike number returned to the field in spring is higher. But the number of grains per spike is more than that of returning to the field in spring. The seed setting rate and the thousand grain weight are not different from each other. The order of the calculated yields of the different processes from high to low is: returning to fields in autumn, returning to fields in spring and no returning to fields areas. The effect of different treatments on different test varieties is also different. The straw returning has good yield increasing effect on varieties with strong tillering capability such as Jihong 9, and has less influence on varieties with weak tillering capability such as Jinong 853. In which jinong 853 also shows a yield reduction under the autumn returning condition (table 3).

TABLE 3 yield Components and yields

A,: it indicates that there are differences in the levels of 5%, 1% and 0.1%, respectively. ns: indicating that there is no difference.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. A method for returning rice straws to fields by water raking slurry in autumn is characterized by comprising the following steps:

2. The method for returning rice straw to the field by raking water in autumn as claimed in claim 1, wherein the harvesting, crushing and spreading in the step (1) are specifically as follows: the height of the harvested stubble is less than or equal to 20cm, the length of the crushed rice straw is less than or equal to 10cm, and the thickness of the rice straw spread in the field is less than or equal to 10 cm.

3. The method for paddy rice straw autumn water raking and pulp returning to the field as claimed in claim 2, wherein the soil layer above 5cm after irrigation and field soaking in the step (2) becomes soft.

4. The method for returning rice straw to the field by water raking and pulp in autumn as claimed in claim 1, wherein the step (1) adopts a combine harvester to harvest, crush and spread the rice straw.

5. The method for returning rice straw to field by water raking slurry in autumn as claimed in any one of claims 1 to 4, wherein the rotary tillage in step (3) does not maintain a significant water layer in the field before rotary tillage, so that more than 80% of the soil surface of the paddy field can not be seen.

6. The method for returning rice straw to field by water raking and pulp in autumn as claimed in claim 5, wherein the rotary tillage and the rotary tillage time of the step (3) are separated by one working width, and the specific working method is implemented as follows:

(1) making a working width from the ground and starting rotary tillage;

(5) and finally, carrying out rotary tillage on the periphery of the land.

7. The method for returning rice straw to field by water raking slurry in autumn as claimed in claim 6, wherein the rotary tillage in the step (3) is carried out, the rotary tillage depth is more than 20cm, the ground is flat, the height difference is less than or equal to 4cm, and the rice straw is completely mixed in the slurry.