立式深旋松耕对半干旱区饲草玉米水分利用和产量的影响

在半干旱区研究立式深旋松耕的土壤水分和产量效应,为饲草玉米增产增效提供理论依据。2017-2019年在定西市安定区设传统旋耕(TT)、深旋耕(DT)和立式深旋松耕(VRT)3种耕作方式,分析立式深旋松耕对饲草玉米土壤贮水量、花前花后耗水、单株鲜重和干重以及产量和水分利用效率的影响。研究结果表明,与DT和TT相比,VRT能够提高干旱年份对土壤水分的吸收利用,使得花期60~180 cm土层的土壤贮水量降低10.0%和7.6%,180~300 cm土层降低17.6%和18.5%,花前0~300 cm土层的土壤耗水量提高14.6%和13.8%,生育期总耗水量增加6.1%和9.2%,2018和2019年生育期总耗水量分别提高2.0%和7.9%、10.1%和14.9%,收获期单株鲜重增加2.4%~16.2%、干重增加1.0%~7.8%,籽粒产量增加2.4%~38.6%,群体生物量增加3.4%~16.2%。立式深旋松耕改善了土壤环境,提高了土壤耗水量,增加了饲草玉米产量和生物量,尤其在干旱年份增产增效显著,在半干旱区具有明显的抗旱增产作用。

Effects of vertical rotary sub-soiling tillage on water use and yield of forage maize on semiarid land

This research was aimed at the development of high-yield and high-efficiency tillage techniques for the production of rain-fed forage maize in semi-arid areas of China. A long-term (2017-2019) field experiment consisting of three treatments: traditional tillage (TT), deep tillage (DT), and vertical rotary sub-soiling tillage (VRT), was carried out in the Loess Plateau, Northwest China. VRT is a recently developed tillage technique designed to break up the compacted soil layer formed just beneath the cultivated layer after repeated cycles of annual rotary tillage. We had investigated the effects of VRT on soil water storage (SWS), crop evapotranspiration (ETc) before and after anthesis, fresh and dry weights per plant, grain yields as well as water use efficiency (WUE). It was found that VRT significantly improved the infiltration of soil moisture to deeper layers, especially in dry years. At the anthesis stage, VRT decreased SWS by 7.6%-10.0% in 60-180 cm layer, and by 17.6%-18.5% in the 180-300 cm layer, compared to DT and TT in the dry year. Prior to the anthesis, SWS of VRT was increased by 13.8%-14.6% in the 0-300 cm layer, and the total ETc of VRT was increased by 6.1%-9.2%, respectively. Compared with DT and TT, VRT increased total ETc by 2.0%-7.9% in 2018, and by 10.1%-14.9% in 2019. At harvest, VRT increased fresh weights per plant by 2.4%-16.2%, dry weights per plant by 1.0%-7.8%, grain yields by 2.4%-38.6%, and population biomass by 3.4%-16.2%. It can be concluded that VRT is a drought-resistant and yield-enhancing tillage technique that is suitable for rain-fed forage maize production in semi-arid areas of the Loess Plateau. The data indicate VRT, improves the soil environment and enhances crop growth, development and yield. The benefits of VRT are more pronounced in dry years.