水旱轮作秸秆还田条件下氮肥调控和钾肥替代效应研究

发布时间：2018-08-07 20:42

【摘要】：秸秆是农业生产中一种重要的可再生资源。采用秸秆还田的方式不但可以在培肥土壤的同时减少农业生态环境的污染,而且可以保持土壤生产力促进粮食增产稳产的效果。随着秸秆还田技术的推广力度不断加大,在秸秆还田的基础上如何调控化肥的施用从而保证资源的高效利用已经成为当前的研究热点。本研究通过在湖北省多点开展不同轮作模式秸秆还田条件下的氮肥调控及钾肥替代试验,研究秸秆还田条件下氮肥用量及不同基追比的施肥效果以及秸秆替代钾肥效果,以期为秸秆还田条件下氮肥和钾肥的合理施用提供理论依据。主要研究结果如下:1.水旱轮作秸秆还田条件下氮肥调控研究结果表明,单季、1年轮作及连续2年轮作秸秆还田条件下均表明等氮量投入下,秸秆还田相比较秸秆不还田水稻、油菜和小麦产量、地上部生物量及氮素吸收量均呈现不同程度地增加。单季秸秆还田条件下高量施用氮肥(水稻195 kg N/hm2,油菜210 kg N/hm2,小麦180 kg N/hm2)相比较常量氮肥习惯3次施用水稻、油菜和小麦产量、地上部生物量及氮素吸收量均无显著提高;而1年轮作及连续2年轮作秸秆还田条件下,高量施用氮肥对稻油轮作系统各指标无显著影响,但对稻麦轮作系统作物均有显著提高作用。1年轮作下,高量氮肥3次施用配合秸秆还田相比较常量氮肥习惯3次施用水稻和小麦平均增产量为632和564 kg/hm2,增产率分别达6.85%和10.67%;地上部氮素吸收量平均分别增加11.54和23.57 kg N/hm2,增幅分别达7.88%和21.28%;2年轮作下,水稻和小麦平均增产量分别为429和377 kg/hm2,增产率分别达4.71%和7.63%,地上部氮素吸收量平均分别增加13.98和15.27 kg N/hm2,增幅分别达8.81%和13.10%。2.单季、1年及连续2年秸秆还田结果均表明,常量氮肥2次施用配合秸秆还田处理的产量、地上部生物量及氮素吸收量可以达到或优于常量氮肥习惯3次施用的水平;就氮肥利用率而言,水稻、油菜和小麦均表现出常量投入即可获得较高的氮肥偏生产力,等氮量投入下,秸秆还田效果要优于秸秆不还田,且秸秆还田条件下氮肥两次施用可以显著提高氮肥利用率。因此,在秸秆还田条件下2种水旱轮作模式均可以通过减少氮肥的施用次数(即后肥前移)从而保证作物达到高产或稳产的目的,同时显著提高氮肥利用率。3.水旱轮作秸秆还田条件下钾肥替代研究结果表明,单季、1年及连续2年秸秆还田结果均表明,与不施钾处理(CK)相比,施钾和秸秆还田均可以不同程度地增加水稻、油菜和小麦的产量、地上部生物量和钾素吸收量,3种供钾土壤产量增幅效果表现为低等供钾(12.51%—126.33%)中等供钾(5.57%—24.54%)高等供钾(2.55%—12.77%),各处理产量增幅效果以秸秆配施钾肥处理较好。高等供钾条件下,+S处理作物产量均可以达到+K处理水平;中等供钾条件下,S+1/2K处理作物产量可以达到+K处理水平;而低等供钾条件下,水稻季S+3/4K处理、油菜和小麦季S+1/2K处理可以达到+K处理产量。就钾素利用率而言,秸秆不还田条件下农学利用率和吸收利用率均高于秸秆还田条件下钾素利用率,水稻季钾素农学利用率和吸收利用率高于旱地作物(油菜、小麦),且高等供钾土壤钾素农学利用率(0.7—4.5 kg/kg)和吸收利用率(9.0%—94.9%)均要低于中等供钾(农学利用率0.8—12.2 kg/kg,吸收利用率11.9%—119.3%)和低等供钾土壤(农学利用率1.6—37.1 kg/kg,吸收利用率19.7%—119.3%)。4.通过计算土壤-作物系统钾素表观平衡发现,水稻季收获后各处理土壤钾素均处于亏缺的状况,但秸秆还田处理亏缺量要远小于秸秆不还田处理,而油菜和小麦季收获后秸秆还田各处理相比较秸秆不还田处理均可以扭亏为盈(油菜季盈余量平均为21.83—103.15 kg K2O/hm2,小麦季盈余量平均为23.50—95.93 kg K2O/hm2),说明秸秆还田可以明显缓解土壤钾素亏缺的状况;通过一元二次方程和线性方程拟合秸秆还田条件下钾肥用量和作物产量之间的关系,比较+K处理产量得到适宜钾肥用量。秸秆还田条件下水稻、油菜和小麦3种作物在高钾、中钾和低钾田块的钾肥适宜施用量平均分别为29 kg K2O/hm2、32 kg K2O/hm2、48 kg K2O/hm2,与目前钾肥施用量60 kg K2O/hm2相比,高钾地块可减少钾肥用量51.7%、中钾地块可减少46.7%、低钾地块可减少20.0%。周年轮作秸秆还田条件下,稻油轮作钾肥用量为31 kg K2O/hm2,减少幅度为48.3%;稻麦轮作钾肥用量为33 kg K2O/hm2,减少幅度为45.0%。
[Abstract]:Straw is an important renewable resource in agricultural production. The method of straw returning can not only reduce the pollution of the agricultural ecological environment while the soil is fertilized, but also can maintain the effect of soil productivity and increase the yield and stable yield of grain. With the increasing of straw returning technology, it is based on the straw returning to the field. How to regulate the application of chemical fertilizer so as to ensure the efficient utilization of resources has become a hot spot of research. In this study, the nitrogen fertilizer regulation and potassium fertilizer replacement test under different crop rotation modes in Hubei province were carried out. The application of nitrogen fertilizer and different base chasing under straw returning conditions and straw replacement were studied. The effect of potassium fertilizer is expected to provide a theoretical basis for rational application of nitrogen fertilizer and potassium fertilizer under the condition of straw returning. The main results are as follows: 1. the results of nitrogen fertilizer regulation under the condition of returning straw to field under water and drought rotation have shown that the single season, 1 year rotation and 2 years of continuous rotation of straw under the condition of straw returning to the field have shown that the straw returned to the field compared with the straw. Rice yield, rape and wheat yield, aboveground biomass and nitrogen uptake increased in varying degrees. High application of nitrogen fertilizer (rice 195 kg N/hm2, rapeseed 210 kg N/hm2, wheat 180 kg N/hm2) under the single season straw returning condition compared with the normal nitrogen fertilizer used in rice, rape and wheat yield, aboveground biomass and nitrogen. There was no significant increase in the amount of absorption, while the 1 year rotation and 2 years of continuous rotation of straw had no significant effect on the rice oil rotation system, but there was a significant increase in the crop rotation system for rice and wheat crop rotation system, and the high nitrogen fertilizer applied 3 times to the straw return field for 3 times of application of rice under the.1 year rotation. The average yield increased by 632 and 564 kg/hm2, and the yield increased by 6.85% and 10.67%, respectively, and the average increase of nitrogen uptake by 11.54 and 23.57 kg N/hm2, respectively, was 7.88% and 21.28%, respectively, and the average increase of rice and wheat was 429 and 377 kg/hm2 respectively under the 2 year rotation, and the increase of yield was up to 4.71% and 7.63%, and the nitrogen uptake in the upper part of the ground was respectively. The average increase of 13.98 and 15.27 kg N/hm2 respectively, the increase of 8.81% and 13.10%.2. single season respectively, 1 years and 2 consecutive years of straw returning results show that the constant nitrogen fertilizer 2 combined with straw returning yield, the biomass and nitrogen absorption capacity of the upper ground can reach or better than the normal nitrogen fertilizer habits 3 application level; nitrogen fertilizer utilization rate, In the case of rice, rape and wheat, high nitrogen fertilizer partial productivity can be obtained by constant input. Under the input of nitrogen amount, the effect of straw returning is better than that of straw not returning to the field, and the nitrogen fertilizer application rate can be significantly increased by two application of nitrogen fertilizer under the straw returning condition. Therefore, under the condition of straw returning to the field, the 2 types of water and drought rotation modes can be reduced. The use of less nitrogen fertilizer (i.e., the forward shift of post fertilizer) so as to ensure the crops to achieve high or stable yield, and significantly improve the nitrogen utilization rate of.3. under the condition of straw returning under the condition of straw returning. The results of single season, 1 years and 2 consecutive years of straw returning show that potassium application and straw return can be compared with non potassium treatment (CK). The yield of rice, rape and wheat, aboveground biomass and potassium uptake were increased to different degrees. The effect of 3 kinds of potassium supply soil yield increase was lower potassium supply (12.51% - 126.33%) for potassium (5.57% - 24.54%) higher potassium supply (2.55% - 12.77%). The effect of yield increase of each treatment was better with straw combined with potash fertilizer. Under the condition of medium potassium supply, the yield of +S treatment could reach the level of +K treatment, and the yield of S+1/2K treated crop could reach the level of +K treatment under the condition of medium potassium supply, but under the condition of low potassium supply, S+3/4K treatment in rice season, and S+1/2K treatment in rape and wheat season could reach +K treatment yield. The utilization ratio of the potassium and the utilization rate of potassium in rice is higher than that of the dry land crops (rape, wheat), and the utilization ratio of potassium in higher potassium soil (0.7 - 4.5 kg/kg) and the absorption and utilization ratio (9% - 94.9%) are lower than that of moderate potassium supply (agronomic utilization rate of 0.8 - 12.2 kg/kg). The utilization rate of 11.9% - 119.3%) and low potassium supply soil (agricultural utilization rate 1.6 - 37.1 kg/kg, absorption and utilization ratio 19.7% - 119.3%).4. by calculating the apparent balance of soil crop system potassium found that the soil potassium in each treatment after the harvest of rice season was in the deficit condition, but the loss of straw returning to field was much less than that of straw returning. After the rape and the wheat season harvest, the straw returning to the field can turn to profit (the average of 21.83 - 103.15 kg K2O/hm2 for the rape season surplus, the average of the wheat season surplus is 23.50 - 95.93 kg K2O/hm2), which shows that the straw returning can obviously alleviate the condition of soil potassium deficiency; through the two times equation of one dollar The relationship between the amount of potassium fertilizer and crop yield was fitted with the linear equation, and the suitable amount of potassium fertilizer was compared with the yield of +K treatment. Under the condition of straw returning, the suitable amount of potassium fertilizer for 3 crops in rice, rape and wheat in high potassium, medium potassium and low potassium fields was 29 kg K2O/hm2,32 kg K2O/hm2,48 kg K2O/hm2. At present, compared with 60 kg K2O/hm2, potassium fertilizer can be reduced by 51.7% of potassium fertilizer and 46.7% of medium potassium massif is reduced. Under the condition of 20.0%. anniversary, the amount of potassium fertilizer in rice oil rotation is 31 kg K2O/hm2, the decrease is 48.3%, and the amount of potassium fertilizer in rice wheat rotation is 33 kg K2O/hm2, and the decrease is 45.0%.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S141.4;S143

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