Straw particle plowing and applying technology for rapidly increasing organic carbon in tobacco field soil

Abstract

The invention discloses a straw particle plowing and applying technology for rapidly increasing organic carbon in tobacco field soil, which adopts straw particle fertilizer as a returning raw material and returns to the field in a manner of deeply plowing into soil. According to the technical scheme, a certain amount of straw particles are returned to the field in cooperation with deep ploughing and returning to the field, the content of organic carbon components in soil of soil layers of 0-20 cm and 20-40 cm can be increased at the same time, and the method is an effective measure for promoting soil carbon sequestration.

Description

Technical Field

[0001] The invention relates to the field of plant planting technology, and more particularly to a straw particle tillage technology for rapidly increasing soil organic carbon in tobacco fields. Background Art

[0002] As a new type of organic matter return measure to farmland, straw pelletization not only improves soil fertility but also solves the problem of where a large amount of straw goes, and is an active means to promote the implementation of the straw return policy and the zero-growth action of chemical fertilizers. Previous studies have shown that returning the entire amount of straw pellets to the field significantly increases the organic matter and alkaline nitrogen content of the tillage layer by 8.5% and 6.1% compared with the conventional straw crushing and returning to the field, and increases the dissolved organic carbon (DOC) by 3.0%, which is related to the faster nutrient release rate of straw pellets. It can be seen that returning straw pellets to the field has a positive significance for quickly improving soil nutrients. When previous studies on the effects of straw pellets on soil nutrients, they mostly compared them with crushed straw, and there were few studies combining them with tillage methods and pellet dosage. Many studies have confirmed that tillage depth can affect the content and distribution of soil nutrients. Liu et al. found that when straw pellets were applied at tillage depths of 15 cm, 25 cm, and 45 cm, the organic carbon (SOC) and total nitrogen (TN) in the 0-20 cm, 20-40 cm, and 40-60 cm soil layers were most significantly increased, with the highest increase at a tillage depth of 25 cm, reaching 8.0% and 8.3%, respectively; and the average SOC and TN content in the 0-60 cm soil layer could be greatly increased. Zhang et al. found that in the first year of applying straw pellets to the soil at 15 cm by rotary tillage, the content of soil organic matter, TN, available nitrogen, and effective phosphorus in the 0-20 cm soil could be significantly increased by 8.54%, 4.72%, 6.12%, and 6.25%, respectively, compared with conventional pulverized straw return to the field. Other studies have shown that the amount of straw used affects the nutrient content and composition of the soil by directly changing the base of organic material input. Xu Meng et al. found that pulverized straw at 1800 kg / hm 2 The amount of nitrogen used can significantly increase the content of alkali-hydrolyzed nitrogen in Liaoning brown soil by 7.9% to 40.9%, while 2400kg / hm 2 It is easier to significantly increase the content of available phosphorus and quick-acting potassium in the soil by 50.9% to 498% and 8.77% to 225%; when straw particles were applied to the farmland soil of Shandong Province to a depth of 40cm, it was found that 3600kg / hm 2 1200kg / hm 2 The amount of straw significantly increased soil organic carbon by 4.7% (20-40 cm) and 5.1% (40-60 cm). It can be seen that different tillage methods and straw amounts will significantly affect the distribution of soil nutrients. It is very important to explore the appropriate straw particle amount combined with tillage methods for rapid soil fertilization.

[0003] Tobacco-growing soils need to meet tobacco's huge demand for nutrients, so they must have the characteristics of fast nutrient supply and high content of quick-acting nutrients. However, the current continuous tobacco cropping has led to excessive consumption of nutrients in tobacco-growing soils. Studies have shown that eight years of continuous tobacco planting has led to a decrease in soil dissolved organic carbon by about 11% and a decrease in soil water-stable aggregate content by about 20%, seriously affecting the sustainable development of tobacco field productivity. Considering that returning straw pellets to the field has a positive effect of rapidly improving soil nutrients, applying it to tobacco-growing soil fertilization can fill the research gap in the mechanism of improving tobacco-growing soil nutrients through returning straw pellets to the field, and provide a theoretical basis and technical support for the rapid improvement of tobacco-growing soil nutrients. Summary of the invention

[0004] In view of this, the present invention provides a straw particle tillage technology for rapidly increasing soil organic carbon in tobacco fields, and achieves corresponding effects by setting reasonable amounts and methods of returning to the soil.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A straw pellet tillage technology for rapidly increasing soil organic carbon in tobacco fields comprises the following steps:

[0007] Use straw granular fertilizer as the raw material for returning to the field and return it to the field by deep plowing.

[0008] Preferably, the preparation method of the straw granular fertilizer is:

[0009] (1) Using corn stalks of the season, taking air-dried whole corn stalks and crushing them into 0.5-1.0 cm, adding appropriate amount of water and putting them into a small granulator, granulating them under the condition of 0.4 MPa steam pressure in the conditioner, and air-drying them after granulation, the granules are cylindrical with a diameter of 0.4 mm and a length of 1-2 cm;

[0010] (2) Adding fertilizer and straw-rotting-promoting fungi Bacillus subtilis to the corn straw pellets obtained in step (1), wherein the addition amount of each component is: NH 4 + -N 5.5kg / t, NO 3 - -N 2.0kg / t, P 2 O 5 7.5 kg / t, K 2 O 6.0kg / t, Bacillus subtilis 3kg / t.

[0011] Furthermore, ridging and fertilizer application are also included. The amount of fertilizer added to the straw pellets + the total amount of fertilizer applied during ridging is N 76.95 kg / hm 2 , P 2 O 5 76.95 kg / hm 2and K 2 O 193.50kg / hm 2 , apply chemical fertilizers in strips during ridge forming.

[0012] Preferably, the straw pellet fertilizer application rate is 6750kg / hm 2 .

[0013] Preferably, the deep plowing depth is 35-40 cm.

[0014] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a straw particle tillage technology for rapidly increasing soil organic carbon in tobacco fields, which has the following beneficial effects:

[0015] Returning a certain amount of straw pellets to the fields combined with deep plowing can simultaneously increase the content of soil organic carbon components in the 0-20 cm and 20-40 cm soil layers, which is an effective measure to promote soil carbon sequestration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0017] Figure 1 This is the DOC / SOC change chart of 0-20cm and 20-40cm soil layers from 2016 to 2018. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1

[0020] Overview of the test site: Field experiments were conducted in Jiayue Town, Zhucheng City, Shandong Province (119°06′E, 36°01′N) from 2016 to 2018. The local altitude is 130m, the climate type is temperate monsoon climate, the average annual sunshine hours are 2578.4h, the average annual temperature is 12.3℃, the average annual precipitation is 773mm, and the frost-free period is 232d. The test site adopts a flue-cured tobacco-winter fallow planting mode, the farming method is mainly rotary tillage, the soil type is brown soil, and the soil texture is loamy clay (international system: sand 12.51%, silt 44.65%, clay 42.90%). The basic physical and chemical properties of the soil are shown in Table 1.

[0021] Table 1 Basic physical and chemical properties of soil

[0022]

[0023] Experimental Design:

[0024] This test setting G1: 2250kg / hm 2 , G2: 4500kg / hm 2 and G3: 6750kg / hm 2 There were 3 different straw pellet dosages, 2 tillage patterns of alternate year deep tillage (T) and continuous year rotary tillage (R), with conventional rotary tillage + no straw application as the control (RG0), a total of 7 treatments (as shown in Table 2), each treatment was replicated 3 times, and a randomized block design was used. Each plot was 72 m 2 . To ensure that the input time and input amount of each treatment straw pellet are the same, the straw pellets were applied in the deep plowing years (2016 and 2018). The straw pellet fertilizer was developed by the research team, using corn straw of the season (containing 42.69% carbon, 1.15% nitrogen, 0.10% phosphorus, and 0.98% potassium). The whole corn straw was air-dried and crushed to 0.5-1.0 cm. After adding water, it was put into a small granulator and granulated under the condition of 0.4 MPa steam pressure in the conditioner. After the granules were made, they were air-dried and the granules were cylindrical with a diameter of 0.4 mm and a length of 1-2 cm. Then, chemical fertilizers and straw decay-promoting bacteria Bacillus subtilis were added to the prepared corn straw pellets, among which NH 4 + -N 5.5kg, NO 3 - -N2.0kg, P 2 O 5 7.5kg, K 2O 6.0kg and Bacillus subtilis 3kg. The TG treatment group used a straw burying plow to turn the straw particles deep into the soil, with a 1004 tractor as the traction power (power 73.5Kw), and the tillage depth was about 35cm; the RG treatment was routine rotary tillage every year, with a tillage depth of 15cm, so that the straw particles were mixed with 0-15cm soil. Then the conventional ridging and fertilizer application were carried out, and the total amount of fertilizer application was N 76.95kg / hm 2 , P 2 O 5 76.95kg / hm 2 and K 2 O 193.50kg / hm 2 , which includes the amount of fertilizer applied separately and the amount of fertilizer added during the production of straw pellets. The fertilizer applied separately is applied in strips during ridge formation. The test crop is NC55 flue-cured tobacco, which is transplanted in early May every year. Four rows of tobacco are planted in the field, with a plant spacing of 0.5m and a row spacing of 1.2m. There are 120 tobacco plants.

[0025] Table 2 Experimental design table

[0026] No. Experimental treatment RG0 Rotary tillage + no returning of straw to the field TG1 <![CDATA[Deep plowing (35 cm) + 2250 kg / hm of straw pellets 2 <!-- 3 -->]]> TG2 <![CDATA[Deep plowing (35 cm) + 4500 kg / hm of straw pellets 2 > TG3 <![CDATA[Deep plowing (35 cm) + 6750 kg / hm of straw pellets 2 > RG1 <![CDATA[Rotary tillage (15 cm) + 2250 kg / hm of straw pellets 2 > RG2 <![CDATA[Rotary tillage (15 cm) + 4500 kg / hm of straw pellets 2 > RG3 <![CDATA[Continuous rotary tillage (15 cm) + 6750 kg / hm of straw pellets 2 >

[0027] Measurement indicators and methods:

[0028] Sample collection: From 2016 to 2018, field soil samples were collected and measured on the 20th, 40th, 60th, 80th, and 100th day after flue-cured tobacco transplanting.

[0029] Determination of soil organic carbon (SOC) and dissolved organic carbon (DOC): The soil samples obtained at the end of each year were air-dried and passed through a 2 mm sieve, and then heated in an oil bath to 40 °C. 2 Cr 2 O 7 -FeSO 4 The SOC concentration was determined by oxidation method. Fresh soil samples were filtered through 2 mm, 10.00 g was taken into a centrifuge tube, 50 mL of distilled water was added to make the soil-water mass ratio 1:5, oscillated for 30 min, centrifuged at 4000 r / min for 10 min, and filtered with a 0.45 μm filter membrane to obtain the supernatant. The DOC concentration in the supernatant was determined using a TOC analyzer (multi N / C 3100, Analytik Jena AG, Jena, Germany).

[0030] Data processing:

[0031] Microsoft Excel 2016 was used to organize the experimental data. One-way ANOVA in SAS 9.4 software was used to compare the differences among different treatments (LSD, P<0.05). Two-way ANOVA was used to analyze the interaction between tillage method and straw pellet dosage.

[0032] Experimental results and analysis:

[0033] 1. SOC

[0034] The soil organic carbon content and organic carbon growth rate are shown in Table 3.

[0035] Table 3 Soil organic carbon content and organic carbon growth rate

[0036]

[0037]

[0038] Note: Lowercase letters represent differences among different treatments in the same soil layer, and the difference analysis was at the significance level of P<0.05, the same below.

[0039] Table 3 shows that the application of straw particles can significantly increase the soil SOC content. For the 0-20 cm soil layer, in 2016, the SOC level was significantly different among the treatments, showing TG3>RG3>RG2>TG1, TG2 and RG1. The SOC level of TG3 was the highest, significantly higher than RG0 by 23.5%, followed by RG3, which was significantly higher than RG0 by 17.8%. Under the same tillage method, high-volume return to the field was significantly higher than low-volume return to the field, TG3 was significantly higher than TG1 by 11.3%, and RG3 was significantly higher than RG by 16.7%. In 2017, the SOC content of RG3 and RG2 treatments was the highest, significantly higher than RG0 by 7.7%, and the RG3 treatment was also significantly higher than the TG treatment. In 2018, the SOC significance level was the highest in RG2 and RG3, followed by TG3 and RG1. Among them, RG2 had the highest increase of 23.2% compared with RG0.

[0040] For the 20-40 cm soil layer, in 2016, the SOC significance level was the highest in the TG treatment, followed by the RG2 treatment. In the TG treatment, the soil SOC content gradually increased with the increase in the amount of particles, and the increase was 37.3% to 39.2% compared with RG0. In 2017, all treatments could significantly increase the SOC content compared with RG0, among which TG3 had the highest increase of 20.8%, followed by RG3, reaching 11.8%. In 2018, the SOC content of the TG3 treatment was significantly higher than that of other treatments, 33.3% higher than that of RG0, and other straw return treatments were also significantly higher than RG0 by 19.2% to 21.7%. It can be seen that increasing the amount of straw particles has a significant advantage in increasing the SOC content of 0-20 cm and 20-40 cm soil.

[0041] The results of two-way ANOVA are shown in Table 4.

[0042] Table 4 Two-way ANOVA analysis of the effects of tillage method and straw pellet dosage interaction on soil organic carbon

[0043]

[0044] Two-way ANOVA showed that tillage method, pellet dosage and their interaction all had significant effects on organic carbon content. For the 0-20 cm soil layer, in 2016, tillage method, pellet dosage and their interaction all had extremely significant effects on SOC (P<0.01), among which the F value of fertilizer dosage (130.55) was the highest, indicating that fertilizer dosage was the most significant factor leading to SOC differences among treatments; in 2017, tillage method and straw dosage had extremely significant effects on SOC content (P<0.01); in 2018, tillage method, pellet dosage and their interaction all had extremely significant effects on SOC content (P<0.01), among which the F value of tillage method (45.85) was the highest, indicating that tillage method was the most significant factor leading to SOC differences. For the 20-40 cm soil layer, in 2016, only the tillage method was an extremely significant factor causing the difference in SOC content (P<0.01); in 2017, the effects of tillage method and fertilizer application on SOC reached an extremely significant level (P<0.01), and the interaction between the two reached a significant level (P<0.05); in 2018, tillage method, particle application and the interaction between the two all had extremely significant (P<0.01) effects on SOC.

[0045] 2. DOC

[0046] The soil dissolved organic carbon content and dissolved organic carbon growth rate are shown in Table 5.

[0047] Table 5 Soil dissolved organic carbon content and dissolved organic carbon growth rate

[0048]

[0049] As shown in Table 5, for the 0-20 cm soil layer, in 2016, the application of straw pellets significantly increased the soil DOC content, with the RG3 treatment having the highest significance level, 19.7% higher than RG0, followed by TG3, 11.7% higher than RG0, and TG1 having the lowest increase, 5.3%; in 2017, the RG3, TG1, TG3 and RG2 treatments could significantly increase the soil DOC content compared with CK, with increases of 12.3%, 10.6%, 7.3% and 7.0%, respectively, with the highest significance levels of RG3 and TG1. In 2018, the application of straw pellets could significantly increase the soil DOC content, with TG3 having the most significant increase compared with RG0, up to 54.0%, followed by TG2, up to 45.9%, and TG1 having the lowest, only 8.3%, and TG3 and TG2 had the highest significance levels among the treatments.

[0050] For the 20-40 cm soil layer, in 2016, the significance order among treatments was TG3, TG2, RG3>RG1, RG2, TG1>RG0, among which the DOC content of TG3, TG2 and RG3 increased by about 43.0% compared with RG0; in 2017, the soil DOC content was in the range of 38.2-48.2 mg / kg, with RG3 having the highest significance level, and its DOC content was 26.0% higher than RG0, followed by RG2 and TG3, which were significantly higher than RG0 by about 12.6%. In 2018, the soil DOC content was in the range of 54.8-94.4 mg / kg, with TG2 and TG3 having the highest significance level, and its DOC content was about 72.1% higher than RG0, followed by TG1, which was significantly higher than RG0 by 21.6%. It can be seen that DOC was more significantly affected by different straw particle application methods, and the increase was higher.

[0051] The results of two-way ANOVA are shown in Table 6.

[0052] Table 6 Two-way ANOVA analysis of the effect of tillage method and straw pellet dosage interaction on soil dissolved organic carbon

[0053]

[0054] Two-way ANOVA found that tillage method, particle dosage and their interaction all had significant effects on DOC content. For the 0-20 cm soil layer, in 2016, tillage method, particle dosage and their interaction all had extremely significant effects on DOC (P<0.01), among which the F value of fertilizer dosage (62.77) was the highest, indicating that fertilizer dosage was the main cause of DOC differences; in 2017, fertilizer dosage and their interaction had extremely significant effects on DOC content (P<0.01), among which the F value of their interaction (37.04) was the highest; in 2018, tillage method, particle dosage and their interaction all had extremely significant effects on DOC (P<0.01). For the 20-40 cm soil layer, in 2016, the amount of particles and the interaction between the two were extremely significant (P<0.01) factors causing the differences in DOC content among treatments, the tillage method was a significant (P<0.05) factor, and the amount of fertilizer (F=53.36) was the main reason for the differences; in 2017, the tillage method, the amount of particles and the interaction between the two had extremely significant (P<0.01) effects on the DOC content, among which the amount of fertilizer (F=78.47) was the main reason for the differences; in 2018, the tillage method, the amount of fertilizer and the interaction between the two had extremely significant (P<0.01) effects on the DOC content, and the tillage method (F=1800.68) was the main reason for the differences among treatments.

[0055] 3. DOC / SOC changes

[0056] The ratio of soil DOC to SOC is an important indicator reflecting the impact of different soil management measures on organic matter and can predict the long-term changes in soil organic matter. Figure 1The results showed that in 2016, the DOC / SOC of the 0-20 cm soil layer was in the range of 6.0-7.0, but the different straw pellet application methods did not significantly increase DOC / SOC; while for the 20-40 cm soil layer, the RG3 and RG1 treatments significantly increased DOC / SOC by 8.0%-40.5% compared with RG0 and TG1. In 2017, for the 0-20 cm soil layer, the RG3 and TG1 treatments significantly increased DOC / SOC by about 4.8% compared with RG0, while for the 20-40 cm soil layer, the DOC / SOC of the RG2 and RG3 treatments were 6.79 and 6.53, respectively, which were significantly higher than the other treatments, with the highest increase of 22.5%. In 2018, the DOC / SOC of the TG2 and TG3 treatments in the 0-20 cm soil layer was about 11.8, significantly higher than RG02 by 9.7%, and significantly higher than other treatments; the DOC / SOC of the TG2 and TG3 treatments in the 20-40 cm layer was also significantly higher than the other treatments by 26.5% to 70.1%. It can be seen that different straw pellet application methods have a more significant effect on the soil DOC / SOC in the 20-40 cm soil layer, and increasing the amount of pellets has a positive effect on improving soil DOC / SOC.

[0057] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A straw pellet tillage technology for rapidly increasing soil organic carbon in tobacco fields, characterized in that: The following steps are involved: Use straw granular fertilizer as the raw material for returning to the field and return it to the field by deep plowing.

2. The straw pellet application technology for rapidly increasing soil organic carbon in tobacco fields according to claim 1 is characterized in that: The preparation method of the straw granular fertilizer is: (1) Using corn stalks of the season, taking air-dried whole corn stalks and crushing them into 0.5-1.0 cm, adding water and putting them into a small granulator, granulating them under the condition of a conditioner steam pressure of 0.4 MPa, and air-drying them after granulation, the granules are cylindrical with a diameter of 0.4 mm and a length of 1-2 cm; (2) Adding fertilizer and straw-promoting fungi Bacillus subtilis to the corn straw pellets obtained in step (1), wherein the addition amount of each component is: NH4 + -N 5.5kg / t, NO3 - -N 2.0kg / t, P2O57.5 kg / t, K2O 6.0kg / t, Bacillus subtilis 3kg / t.

3. The straw pellet application technology for rapidly increasing soil organic carbon in tobacco fields according to claim 2 is characterized in that: It also includes ridging and fertilizer application. The total amount of fertilizer added to the straw pellets + the total amount of fertilizer applied during ridging is N 76.95kg / hm 2 、P2O576.95 kg / hm 2 and K2O 193.50kg / hm 2 , apply chemical fertilizers in strips during ridge forming.

4. The straw pellet application technology for rapidly increasing soil organic carbon in tobacco fields according to claim 1 is characterized in that: The application amount of the straw pellet fertilizer is 6750kg / hm 2 .

5. The straw pellet tillage technology for rapidly increasing soil organic carbon in tobacco fields according to claim 1 is characterized in that: The deep plowing depth is 35 cm.

Images