北方旱作区作物产量和水肥利用特征与提升途径

发布时间：2018-04-15 18:52

本文选题：北方旱作区 + 产量　；参考：《中国农业大学》2017年博士论文

【摘要】：北方旱作区是我国重要的粮食生产基地,在保障国家粮食安全中有着重要地位,但该区域粮食生产面临着干旱缺水和土壤供肥不足等资源条件限制,导致作物产量低而不稳。虽然在过去的多年中作物产量大幅提升,但是该区域旱地小麦、玉米产量和水肥利用特征、提升空间及其主要驱动因素仍不清楚。本研究对我国北方旱作区1970-2015年开展的田间试验进行了系统研究和整合分析,获得如下主要结论:(1)探明了北方旱作区旱地小麦、玉米产量和水肥利用效率的变化特征。1980-2015年北方旱作区旱地小麦和玉米的产量平均为3902 kg/ha和7785 kg/ha,WUE平均为11.6 kg/ha.mm和19.1 kg/ha.mm,NUE平均为30.7%和35.1%。1980s至今,小麦、玉米的产量和WUE大幅提高。与1980s相比,2011-2015年小麦和玉米的产量分别提高了 60.2%和54.5%,WUE分别提高了 37.0%和70.5%。1980-2015年,小麦和玉米NUE呈先升高后降低的趋势,分别在2000s和1990s达到最高。小麦产量和WUE随着区域降水量的增加显著提高,玉米产量和WUE在年降水量350 mm区域显著降低,其它区域差异不显著。小麦和玉米的NUE均在年降水量550-650 mm区域显著高于其它降水区域。小麦和玉米的PFP-N和PFP-P随着降水量的增加而显著提高。(2)1980s以来,北方旱作区降水总体呈现降低趋势,对作物产量和WUE的提高不利。化肥投入量的大幅增加和土壤肥力的提升驱动了作物产量和WUE提高。但是施肥量的增加导致了作物PFP和NUE的降低。作物产量、WUE和NUE区域间的差异主要受ET影响,尤其是小麦。不同区域化肥投入和土壤供肥能力的不均衡也导致了作物产量的差异。(3)栽培技术的进步是推动作物产量和WUE提升的重要因素。1980s至今,技术对小麦和玉米产量的贡献分别为19.1%和18.2%、对WUE的贡献均为15.3%。随着时间推移和区域降水量的增加,技术对作物产量和WUE的贡献份额降低。技术对小麦和玉米NUE的贡献则随着年代和降水量的增加呈显著升高的趋势。从单项技术看,地膜覆盖、秸秆覆盖、免耕、深松、平衡施肥等技术均对作物产量和WUE具有较好的提升效果,且多数技术在降水较低区域更优。(4)北方旱作区小麦和玉米高产分别为6823 kg/ha和13149 kg/ha,平均产量分别为高产的的48.4%和53.4%,仍有1倍的提升空间。小麦和玉米WUE最大可实现20.4 kg/ha.mm和34.2 kg/ha.mm。造成作物产量差异的主要原因是土壤供水不足、肥料投入偏低、土壤供肥能力差以及技术应用率低。有效降低土壤蒸发、协调水肥关系、提升土壤供肥能力和加强技术应用是北方旱作区作物产量和水肥效率进一步提高的主要途径。
[Abstract]:Dry farming area in northern China is an important food production base in China, which plays an important role in ensuring national food security. However, grain production in this region is faced with resource constraints such as drought and water shortage and insufficient soil supply of fertilizer, which leads to low and unstable crop yield.Although crop yields have increased significantly in the past few years, the characteristics of wheat and maize yields, water and fertilizer use, the space for improvement and their main drivers in dryland areas in the region are still unclear.In this study, a systematic study and integrated analysis of field trials conducted from 1970 to 2015 in dry farming areas of northern China were carried out. The main conclusions are as follows: 1) the dry land wheat in dry farming areas of northern China has been proved.Characteristics of Maize yield and Water and Fertilizer use efficiency. From 1980 to 2015, the average yields of wheat and maize in dryland areas of North China were 3902 kg/ha and 7785 kg / ha, respectively. The average yields of wheat and maize were 11.6 kg/ha.mm and 19.1 kg / ha.mm nue, respectively, 30.7% and 35..1% respectively, and the yields and WUE of wheat and maize increased significantly from 1980 to present.Compared with 1980's, wheat and maize yield increased by 60.2% and 54.5% respectively in 2011-2015 and 70.5% and 70.5% in 1980-2015, respectively. The NUE of wheat and maize increased first and then decreased, and reached the highest in 2000s and 1990s, respectively.Wheat yield and WUE increased significantly with the increase of regional precipitation, maize yield and WUE decreased significantly in 350mm annual precipitation, but there was no significant difference in other regions.The NUE of wheat and maize were significantly higher than that of other precipitation regions in the precipitation range of 550-650 mm.The PFP-N and PFP-P of wheat and maize increased significantly with the increase of precipitation. Since 1980 s, the precipitation in the dry farming area of North China showed a decreasing trend, which was unfavorable to the increase of crop yield and WUE.The increase of fertilizer input and soil fertility led to the increase of crop yield and WUE.But the increase of fertilization resulted in the decrease of PFP and NUE.The difference of crop yield between Wue and NUE was mainly affected by et, especially wheat.The imbalance of fertilizer input and the ability of soil fertilizer supply in different regions also led to the difference of crop yield. The improvement of cultivation technology was an important factor to promote crop yield and WUE increase from 1980 s to present.The contribution of technology to wheat and maize yield was 19.1% and 18.2%, respectively, and the contribution to WUE was 15.3.As time goes on and regional precipitation increases, the contribution of technology to crop yield and WUE decreases.The contribution of technology to NUE of wheat and maize increased significantly with the increase of age and precipitation.From the point of view of single technique, mulching with mulch, straw mulching, no-tillage, deep loosening, balanced fertilization and other techniques all have better effects on crop yield and WUE.The yield of wheat and maize were 6823 kg/ha and 13149 kg / ha, respectively. The average yield of wheat and maize were 48.4% and 53.4% of that of high yield, respectively.The maximum WUE of wheat and maize can be achieved by 20.4 kg/ha.mm and 34.2 kg / ha.mm.The main reasons for the difference of crop yield are insufficient soil water supply, low fertilizer input, poor capacity of soil fertilizer supply and low application rate of technology.Effective reduction of soil evaporation, coordination of water and fertilizer relationships, enhancement of soil fertilizer supply capacity and enhancement of technical application are the main ways to further improve crop yield and water and fertilizer efficiency in dry farming areas in the north of China.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S512.1;S513

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