深松条件下不同地表覆盖对马铃薯产量及水分利用效率的影响

水分不足是限制旱区作物生长的主要因素,覆盖耕作能够改善土壤的微环境,从而显著提高作物的产量和水分利用效率。为探讨深松结合地表覆盖对土壤物理性状、马铃薯生长、产量及水分利用效率的影响,2013-2015年在宁南旱区采用深松覆盖秸秆、深松覆盖地膜、深松不覆盖3种覆盖耕作模式,以传统耕作不覆盖为对照,对土壤体积质量、团聚体、水分、马铃薯产量和水分利用效率等方面的影响进行了研究。结果表明,与传统耕作相比,深松结合地表覆盖可有效降低耕层土壤体积质量,改善土壤孔隙状况,以深松覆盖秸秆处理效果最佳,深松覆盖秸秆处理0~40 cm平均土壤体积质量较传统耕作降低17.1%。与传统耕作相比,深松覆盖地膜和深松覆盖秸秆处理可使0~40 cm土层0.25 mm机械稳定性团聚体数量显著增加30.7%和17.4%。深松结合不同覆盖方式能有效改善马铃薯生育期0~200 cm土层土壤水分状况,深松覆盖地膜对作物生育前期土壤水分保蓄效果较好,深松覆盖秸秆对生育中后期土壤水分状况的改善效果最佳。深松结合不同覆盖方式下马铃薯植株株高、茎粗及地上部生物量均显著高于传统耕作。作物生育前期以深松覆盖地膜处理效果最佳,中后期以深松覆盖秸秆处理促进作用明显。深松结合地表覆盖能明显提高马铃薯的产量和水分利用效率,深松覆秸秆处理的马铃薯产量、商品薯率和水分利用效率分别较传统耕作处理平均提高37.3%、93.3%和41.2%。通过两年试验研究,在宁南旱区采用深松结合地表覆盖措施具有良好的蓄水保墒效果,对马铃薯生长有利,以深松覆盖秸秆处理的增产和提高水分利用效率效果最为显著。

Effects of different ground surface mulch under subsoiling on potato yield and water use efficiency

Abstract: Water deficiency is the main limiting factor for crop growth in dry-farming areas. Many studies and practices have demonstrated that, mulching tillage can improve the soil microclimate, and significantly increase the yield and water use efficiency of crops. In order to explore the effects of different ground surface methods combined with subsoiling tillage on soil physical characteristics, potato growth, yield and water use efficiency, field fixed position experiment was conducted to study the effect of mulching tillage on soil volume quality, aggregate, water, potato yield and water use efficiency in arid areas of southern Ningxia between 2013 and 2015. The field experiment consisted of the following 4 treatments: straw mulch with subsoiling tillage (ST+JM), plastic film mulch with subsoiling tillage (ST+DM), no mulch with subsoiling tillage (ST), and no mulch with conventional tillage (CT). The no mulch with conventional tillage was used as the control. Our study results showed that, the soil volume quality of the 0-40 cm soil layer under subsoiling combined with mulch was effectively decreased compared with conventional tillage, while the soil total porosity was greatly improved, and especially the straw mulch with subsoiling treatment was the best. During the study, the mean soil volume quality (0-40 cm) under straw mulch with subsoiling treatment was significantly (P<0.05) decreased by 17.1% when compared with the conventional tillage treatment. Our study found that, the subsoiling with ground surface mulch produced signi?cantly higher amounts of >0.25 mm elastic-stable macroaggregates in the 0-40 cm soil layer compared with conventional tillage. The amounts of >0.25 mm aggregates (0-40 cm) under straw mulch with subsoiling and plastic film mulch with subsoiling treatments were signi?cantly (P<0.05) increased by 30.7% and 17.4% respectively compared with the conventional tillage treatment. Subsoiling combined with ground surface mulch greatly improved soil water storage in the 0-200 cm soil layer during the growing stage of potato. The straw mulch with subsoiling and plastic film mulch with subsoiling treatments had the best effect on water conservation; the soil water storage in the 0-200 cm soil layer under the plastic film mulch with subsoiling treatment was significantly higher than the conventional tillage treatment at the early stage of potato, while the straw mulch with subsoiling treatment could significantly improve the soil water content (0-200 cm) in the later growth period. The application of mulching tillage significantly promoted the growth of potato, and the plant height, stem diameter and aboveground biomass of potato under the different ground surface mulching methods with subsoiling were significantly higher than the conventional tillage treatment. The plastic film mulch with subsoiling treatment significantly promoted the growth of potato in the early stage, and the straw mulch with subsoiling treatment significantly promoted the growth of potato in the later growth period. Higher yield and water use efficiency improvement were also achieved under different ground surface mulching methods with subsoiling. The potato yield, commodity rate and water use efficiency under the straw mulch with subsoiling treatment were significantly (P<0.05) increased by 37.3%, 93.3% and 41.2%, respectively, when compared with the conventional tillage treatment. For the plot experiments in 2 years, the ground surface mulch with subsoiling measure can not only effectively decrease soil volume quality, but also significantly improve soil structure, and shows the better soil water conservation ability, therefore promoting the growth of potato; and the straw mulch with subsoiling treatment significantly increases potato yield and water use efficiency in the arid areas of southern Ningxia.