Various no-tillage years with previous residual plastic film mulching improved soil properties and agricultural benefits in an arid region

Abstract

No-tillage (NT) with residual plastic film from an earlier year (NTR) is adopted in arid regions to reduce plastic film residue, decrease soil disturbances, and increase water use efficiency (WUE) and agricultural benefits. However, the effects of NTR on soil crop systems are more complex because of the high disintegrated fraction (DF) of residual plastic film and stronger soil compaction under NT. Additionally, the optimum number of years for NTR is still not elucidated. Therefore, we studied the effects of conventional tillage and NT with a new plastic film mulching (CTN and NTN, respectively) and those of 1, 2, and 3 years of NTR on soil physical properties, soil water content (SWC), maize root and shoot growth, yield, and economic benefits. The experiment was conducted for 3 years in Hetao Irrigation District, China, from 2019 to 2021. The results revealed that the longer the duration of NT (including NTN and NTR), the higher the soil bulk density and lower the total soil porosity than those under CTN in 0–30 cm soil layer. SWC decreased due to the increase in the DF of residual plastic film from NTR. In the third year (2021), SWC under NTR reduced by 5.1 % compared with that under NTN. Additionally, with the increase of NTR years, the maize root and shoot dry biomass and root to shoot ratio clearly decreased under NTR compared with those under CTN and NTN. However, the root volume density of very fine roots under NTR increased significantly in the first 2 years (2019 and 2020) of NT. The yield and WUE decreased slightly under NTR compared with those under CTN in 2019 and 2020; but the net revenue increased by 15.7 % and 9.6 %, respectively. Conversely, the significant decrease in the yield and WUE was observed under NTR compared with those under CTN in 2021 led to a 15.6 % decrease in net revenue. Moreover, a higher sustainability index was observed in the first 2 years. Therefore, NTR with 2 years can be recommended as the optimal local tillage measure with the decrease in the amount of residual plastic film and increased farm economic benefits.