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【目的】通过研究保护性耕作对旱地春玉米土壤有机碳(SOC)、产量及水分利用的影响,分析保护性耕作的增产机制,为旱作农田耕作技术应用提供理论和技术支持。【方法】采用2003~2013年连续11年的田间定位试验,设传统耕作(CT)、少耕(RT)和免耕(NT)3种耕作措施,分析土壤0-20 cm和20-40 cm土层有机碳含量、土壤0-20 cm含水量、作物耗水量、玉米产量和水分利用效率的年际变化和耕作处理间的差异,并对玉米产量与影响因素的相关性进行分析。【结果】1)保护性耕作能有效提高土壤有机碳含量,少耕、免耕处理0-20 cm土层有机碳含量11年平均值较传统耕作分别提高了11.2%和3.4%;至2013年少耕、免耕20-40 cm土层有机碳含量分别较传统耕作增加了5.53和3.29 g/kg;土壤0-20 cm有机碳储量净增加速率分别为C 0.365和0.754t/(hm2·a)。2)保护性耕作具有明显的增产效果,少耕产量最高,增产效果最好2003~2013年均产量为5.83t/hm~2,较传统耕作提高了14.7%;免耕次之,年均产量为5.39 t/hm~2,较传统耕作增产6.1%。3)各耕作处理玉米产量与土壤0-20 cm土层含水量之间存在显著的二次方程关系,与作物耗水量之间具有显著的乘幂方程关系。4)保护性耕作可以增加土壤水分减少玉米生育期内的耗水量,提高水分利用效率,其中免耕土壤0-20 cm土层水分含量最高2003-2013年平均含水量为15.2%,较传统耕作和少耕提高了1.90和1.66个百分点,且生育期耗水量最少2003~2013年均耗水量为403.5 mm,较传统耕作和少耕减少了16.1 mm和7.6 mm;少耕、免耕的水分利用效率较传统耕作分别提高了16.1%和10.2%,降水利用效率较传统耕作提高13.9%和5.8%。【结论】长期保护性耕作可以有效地提高土壤有机碳含量、增加土壤水分、减少作物耗水量,从而显著提高了玉米产量和水分利用效率,3种耕作措施中以少耕效果最好,免耕次之在旱作农田推广少、免耕保护性耕作措施是一种增产、节水的有效途径。
【Objective】 The objective of this study was to investigate the effects of conservation tillage on soil organic carbon (SOC), yield and water use in dryland spring maize. The mechanism of tillage yield increase was analyzed to provide theoretical and technical support for the application of tillage technology in dryland farming. 【Method】 Three kinds of tillage measures, conventional tillage (CT), tillage (RT) and no-tillage (NT), were conducted in the field for 11 consecutive years from 2003 to 2013. Soil 0-20 cm and 20-40 cm Soil organic carbon content, soil 0-20 cm water content, crop water consumption, inter-annual variation of maize yield and water use efficiency and tillage treatment, and the correlation between maize yield and its influencing factors were analyzed. 【Result】 Conservation tillage can effectively increase the content of soil organic carbon. Compared with the traditional tillage, the 11-year average value of organic carbon in zero-tillage treatments increased by 11.2% and 3.4% Compared with the conventional tillage, the organic carbon content of 20-40 cm soil layers in tillage and no-tillage increased by 5.53 and 3.29 g / kg, respectively. The net growth rates of 0-20 cm soil organic carbon in soil and soil were C 0.365 and 0.754 t / (hm 2 · a) . 2) Conservation tillage has obvious yield increasing effect, with the highest tillage yield and the best yield increase. The average yield of 2003 ~ 2013 was 5.83 t / hm ~ 2, which was 14.7% higher than that of traditional tillage. 5.39 t / hm ~ 2, 6.1% more than the traditional farming. 3) There is a significant quadratic relationship between the yield of maize and water content of 0-20 cm soil layer in each tillage process, and has a significant power-equation relationship with crop water consumption. 4) Conservation tillage can increase soil moisture to reduce water consumption during maize growth and improve water use efficiency. Soil moisture in 0-20 cm soil layer of no-tillage soil is the highest. Average water content in 2003-2013 is 15.2%. Compared with traditional tillage And less tillage increased by 1.90 and 1.66 percentage points, respectively, and the minimum water consumption during the growth period was 403.5 mm between 2003 and 2013, which was 16.1 mm and 7.6 mm less than those of the traditional tillage and tillage. The water use of tillage and no tillage The efficiency is 16.1% and 10.2% higher than the traditional tillage respectively, and the precipitation efficiency is 13.9% and 5.8% higher than the traditional tillage. 【Conclusion】 Long-term conservation tillage can effectively increase soil organic carbon content, increase soil moisture and reduce water consumption of crops, thus significantly increasing maize yield and water use efficiency. Among the three tillage measures, the least tillage effect is the best, and the no tillage Followed by less promotion in dry farmland, no-tillage conservation tillage measures is an effective way to increase production and water conservation.