稻—菜轮作条件下秸秆还田与化肥减量配施对作物产量及土壤性质的影响

发布时间：2018-05-04 09:28

本文选题：秸秆还田 + 减量施肥　；参考：《西南大学》2015年硕士论文

【摘要】：农作物秸秆是世界上数量最多的一种农业生产副产品。我国秸秆资源巨大,近几年作物秸秆的生产量均在7亿t以上,但对于秸秆的综合利用还没有形成完整有效的政策机制,作物秸秆的利用效率依旧较低。此外,秸秆直接焚烧既造成资源浪费,也造成环境污染。农业生产中化肥的过量施入,既造成士壤地力下降,也对地下水及江河湖泊造成污染,是农业面源污染的重要来源。作物秸秆含有大量N、P、K等营养元素、微量元素、丰富的有机质,是一种低廉的有机物料。秸秆还田能够把作物吸收的大部分营养元素归还到土壤,同时秸秆还田又能减少化肥的施用,达到改良土壤性状等作用,是秸秆资源有效利用最直接、最有效的途径,也是农业可持续发展的重要途径。本文通过2年的田间定位试验,分别设置氮磷钾全量施肥(NPK)、90%氮磷钾施肥+秸秆还田(90%NPK+S)、80%氮磷钾施肥+秸秆还田(80%NPK+S)、70%氮磷钾施肥+秸秆还田(70%NPK+S)、50%氮磷钾施肥+2倍秸秆还田(50%NPK+SS)共5个处理,研究了秸秆还田配合减量施肥对土壤物化性状、生物学性状、土壤养分状况以及作物产量及其构成因素、生长性状、品质等的影响,旨在为废弃秸秆资源化利用提供科学依据,主要研究结果如下1、稻-蔬轮作条件下连续秸秆覆盖还田配合减量施肥对士壤理化性质有较大的影响。与只施化肥处理相比,收获三季后,秸秆还田处理的士壤容重降低0.020～0.11 g·cm-3；pH值提高0.060-0.55；有机质提高2.55～12.9g·kg-1;全氮含量提高0.0290～0.941kg·-1;全磷含量提高0.033～0.392 g·kg-1;全钾含量提高-0.200～6.50g·kg-1;速效氮含量提高18.3～65.5 mg·kg-1;速效磷含量提高0.200-13.7mg·kg-1;速效钾含量提高4.20～61.5 mg·kg-1。由此可知,与全量施入氮磷钾处理相比,秸秆还田配合减量施肥可以降低耕层土壤的容重,改善耕层士壤容重；有效提高耕层土壤pH值,使之接近中性；同时,还可以提高耕层土壤有机质、全量氮磷钾含量、速效氮磷钾含量。其中,70%-80%NPK+全量秸秆还田对土壤理化性质的改良效果最显著。2、稻-蔬轮作条件下连续秸秆覆盖还田配合减量施肥对土壤生物学性状影响较大。秸秆还田后,土壤转化酶、蛋白粉、过氧化氢酶、脲酶和酸性磷酸酶活性均有显著的提高,高于只施化肥的NPK处理。与只施化肥处理相比,水稻(2013)、儿菜(2013)、水稻(2014)收获季后,秸秆还田处理的土壤转化酶活性提高11.5%、11.0%、5.8%；蛋白酶活性提高19.3%、29.3%、23.8%；过氧化氢酶活性提高9.1%、6.4%、0.6%：脲酶活性提高15.6%、45.9%、48.4%；酸性磷酸酶活性提高50.8%、40.3%、6.6%。其中,70%～80%NPK+全量秸秆还田对于土壤酶活性的提升效果最显著。此外,通过分析土壤养分与土壤酶活性的相关关系还发现,土壤有机质、pH、全量养分和速效养分均对脲酶、过氧化氢酶、转化酶、酸性磷酸酶和蛋白酶活性的相关性均达到极显著正相关,土壤容重与各种酶活性的相关性达到极显著负相关,说明较好的土壤理化性质对改善土壤酶活性有着积极地促进作用。3、稻-蔬轮作条件下连续秸秆覆盖还田配合减量施肥对作物产量、经济效益等也有较大影响。秸秆覆盖还田配合减量施肥,可以提高水稻产量,增产3.03%～17.89%。其中以90%NPK+全量秸秆还田和50%NPK+两倍秸秆还田处理增产效果最好,分别增产17.06%和16.31%。通过水稻产量构成因素相关性分析得到,对水稻产量起主要作用的是水稻的有效穗数和结实率(r=0.811**、0.514**),秸秆还田以增加水稻的有效穗数和结实率来提高产量。同时,秸秆还田配合减量施肥可以使儿菜增产12.18%～36.36%,增加氨基酸总量、维生素C含量、还原糖含量,一定程度上降低NO3-N含量,对于儿菜品质的提高有积极作用。此外,秸秆还田配合减量施肥可以增加水稻和儿菜的产值及产投比,有效提高水稻和儿菜的经济效益。从水稻和儿菜产量及经济效益综合来看,50%NPK+两倍秸秆还田处理平均产投比最高,达到21.6、11.6,是最经济实惠的施肥策略。4、稻-蔬轮作条件下连续秸秆覆盖还田配合减量施肥对水稻品质、氮磷钾吸收量等有较大影响。水稻不同器官中的氮、磷含量表现为籽粒秸秆,钾含量表现为秸秆籽粒。通过相关性分析发现,秸秆还田配合减量施肥与植株氮含量呈负相关关系(r=-0.298、-0.228),与其余各项指标均呈正相关关系。说明秸秆还田配合减量施肥可以提高水稻植株磷钾含量,降低植株氮含量。而水稻产量与植株氮磷钾含量均呈正相关关系,说明植株氮磷钾含量可能影响水稻产量的变化。对作物氮磷钾吸收量的相关分析发现秸秆还田配合减量施肥与作物吸氮量呈负相关关系(r=-0.244),与作物吸磷钾量呈正相关关系(r=0.629、0.567),说明秸秆还田配合减量施肥可以增加作物磷钾吸收量,减少作物氮素吸收量。此外,植株氮磷钾含量及吸收量之间也存在一定的相互作用。综上研究结果得到,70～80%NPK+全量秸秆还田(水稻季施入尿素170.8～195.0kg·hm-2、过磷酸钙189.2～215.8kg·hm-2、氯化钾60.8～69.2kg·hm-2、秸秆7500kg·hm-2,儿菜季施入尿素383.6～ 428.4 kg·hm-2、过磷酸钙266.9～305.1 kg·hm-2、氯化钾136.3～155.7 kg·hm-2、秸秆7500kg·hm-2)是该地区稻-蔬轮作模式的最优施肥方式。秸秆还田是水旱轮作条件下提高土壤肥力和增加作物产量的重要途径。
[Abstract]:Crop straw is one of the most important agricultural by-products in the world. The straw resource in China is huge. The production of crop straw is more than 700 million T in recent years. However, the comprehensive utilization of straw has not formed a complete and effective policy mechanism. The utilization efficiency of crop straw is lower than that of the old. In addition, the direct incineration of straw not only causes resources. The excessive application of chemical fertilizer in agricultural production can not only cause the decline of soil fertility, but also cause pollution to the groundwater and rivers and lakes. It is an important source of agricultural non-point source pollution. The crop straw contains a large amount of nutrient elements such as N, P, K, trace elements and rich organic matter. It is a kind of low organic material. Straw return can be returned to the field. Enough nutrient elements absorbed by the crop are returned to the soil, while straw returning can also reduce the application of chemical fertilizer and improve soil properties. It is the most direct and effective way for the effective utilization of straw resources. It is also an important way for the sustainable development of agriculture. In this paper, nitrogen, phosphorus and potassium are set up by 2 year field positioning test. Fertilization (NPK), 90% nitrogen, phosphorus and potassium fertilizer + straw returning (90%NPK+S), 80% nitrogen, phosphorus and potassium fertilization + straw returning (80%NPK+S), 70% nitrogen, phosphorus and potassium fertilization + straw returning (70%NPK+S), 50% nitrogen, phosphorus and potassium fertilizer and +2 times straw returning (50%NPK+SS) were 5 treatments. The soil physical and chemical properties, biological characters and soil nutrient status were studied. The effects of crop yield and its components, growth traits, quality and so on in order to provide scientific basis for the utilization of waste straw resource. The main results are as follows. The main results are as follows: 1, under the condition of rice and vegetable rotation, continuous straw mulching and reducing fertilization have a great influence on the physical and chemical properties of the soil. Compared with the only fertilizer treatment, the straw is harvested after three seasons. The soil bulk density decreased by 0.020 to 0.11 G. Cm-3, pH value increased by 0.060-0.55, the organic matter increased by 2.55 to 12.9g. Kg-1, the total nitrogen content increased by 0.0290 to 0.941kg. -1, the total phosphorus content increased by 0.033 to 0.392 g kg-1; the content of total potassium increased -0.200 to 6.50g. .200-13.7mg. Kg-1; the content of available K increased by 4.20 ~ 61.5 mg. Kg-1., as a result, compared with the total amount of N, P and K treatment, straw returning and reducing fertilizer could reduce the bulk density of soil in the plough layer, improve the soil bulk density of the plough layer, improve the soil pH value of the plough layer and make it close to neutral; meanwhile, the organic matter in the plough soil can be improved, and the whole soil organic matter can be improved. The content of nitrogen, phosphorus and potassium, and the content of available nitrogen, phosphorus and potassium. Among them, the improvement effect of 70%-80%NPK+ full straw returning to soil physical and chemical properties was most significant.2, under the condition of rice and vegetable rotation, continuous straw mulching and reducing fertilizer had great influence on soil biological characters. After returning to the field, soil soil invertase, protein powder, catalase, urease and acidity were found. The activity of phosphatase was significantly higher than that of NPK treated with chemical fertilizer only. Compared with only fertilizer treatment, the activity of soil invertase was increased by 11.5%, 11%, 5.8% after rice (2013), 2013, and rice (2014), and the activity of protease increased by 19.3%, 29.3%, 23.8%, and the activity of catalase increased 9.1%, 6.4%, 0.6%: Urease activity increased by 15.6%, 45.9%, 48.4%, acid phosphatase activity increased by 50.8%, 40.3%, 6.6%., and 70% ~ 80%NPK+ total straw returning to soil enzyme activity was the most significant. In addition, the relationship between soil nutrients and soil enzyme activity was also found, soil organic matter, pH, total nutrient and available nutrients were urease, The correlation of catalase, invertase, acid phosphatase and protease activity reached very significant positive correlation. The correlation between soil bulk density and the activity of various enzymes reached a very significant negative correlation, indicating that better soil physical and chemical properties had a positive effect on improving soil enzyme activity with.3 and continuous straw mulching under rice and vegetable rotation. The effect of reducing fertilization on crop yield and economic benefit also have great influence. Straw mulching and reducing fertilizer can increase rice yield and increase yield by 3.03% ~ 17.89%., with the best yield of 90%NPK+ full straw returning and two times 50%NPK+ straw returning to the field, and increase yield 17.06% and 16.31%. through rice yield components respectively. The results showed that the effective spike number and seed setting rate (r=0.811**, 0.514**) were the main effects on rice yield. The straw returned to the field to increase the number of effective panicles and seed setting rate to increase the yield. At the same time, the yield increased by 12.18% to 36.36%, the total amount of amino acids, the content of vitamin C, and the reduction of vitamin A was reduced. The content of sugar, to a certain extent, reduced the content of NO3-N, has a positive effect on the improvement of the quality of Chinese cabbage. In addition, straw returning and reducing fertilization can increase the output value and yield ratio of rice and cabbage, and effectively improve the economic benefits of rice and cabbage. From the comprehensive view of rice and vegetable yield and economic benefits, two times the 50%NPK+ straw is returned to the field. The average output ratio is the highest, reaching 21.6,11.6, which is the most economical and economical fertilization strategy.4. Under the condition of rice and vegetable rotation, continuous straw mulching and reducing fertilization have a great influence on the quality of rice and the absorption of N, P and K. The nitrogen and phosphorus content in different organs of rice is shown as grain straw and potassium content is shown as straw kernel. It was found that there was a negative correlation between straw returning and reduced fertilizer and the nitrogen content of plant (r=-0.298, -0.228), and there was a positive correlation with the other indexes. The content of nitrogen, phosphorus and potassium may affect the change of rice yield. The correlation analysis of nitrogen, phosphorus and potassium uptake of crops showed that straw returning and reducing fertilizer had a negative correlation with crop nitrogen uptake (r=-0.244), and there was a positive correlation with crop phosphorus uptake (r=0.629,0.567), indicating that straw returning with reduced fertilizer could increase crop phosphorus and potassium absorption. In addition, there was a certain interaction between the nitrogen, phosphorus and potassium content of the plant. In addition, the results obtained from 70 to 80%NPK+ total straw returned to the field (170.8 ~ 195.0kg / hm-2 of urea in rice season, 189.2 ~ 215.8kg hm-2 of superphosphate, 60.8 ~ 69.2kg hm-2 of potassium chloride, 7500kg. Hm-2 of straw. Urea 383.6 ~ 428.4 kg / hm-2, calcium superphosphate 266.9 ~ 305.1 kg hm-2, potassium chloride 136.3 ~ 155.7 kg hm-2, straw 7500kg. Hm-2) is the best fertilization mode of rice and vegetable rotation in this area. Straw returning is an important way to improve soil fertility and increase crop yield under the condition of water and drought rotation.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4;S143

【参考文献】