Tillage and Deficit Saline Water Irrigation with Mulch in Sorghum-Wheat
Cropping System Improve Soil Chemical and Biological Properties and
Reduce Soil Salinity in Semi-arid Northwest India
Abstract
Inadequate access to fresh water during dry winter season is a major
limitation in realizing high crop yield. Using available saline water
except at germination and crown root initiation stages can be a
practical solution to meet water demand. Therefore, a field experiment
was conducted in saline soils to investigate the effect of tillage and
rice straw mulch on soil properties and its interrelation with yield of
rainfed sorghum (RS) and irrigated wheat (IW) uUnder three levels of
saline irrigation of 100, 80 and 60% water requirement (WR) of wheat.
Reduced (RT), conventional (CT) and zero tillage (ZT) were taken in main
plots and saline irrigation (ECiw 8.0 dS m-1) and rice straw mulch (0
and 5 Mg ha-1) in subplots. Zero tillage significantly reduced the wheat
yield compared to CT and RT. Interaction between RT, mulching and 60WR
markedly increased the sorghum fodder yield. Deficit saline irrigation
(60WR) caused a significant reduction in soil salinity (ECe) after every
crop cycle. Soil microbial biomass C, N (MBC, MBN), dehydrogenase (DHA),
urease (Ur), and alkaline phosphatase (AlP) decreased with increment of
ECe. Irrigation with 60WR and ZT maintained higher values of MBN. The
α-glucosidase, MBC, ECe, available N, MBC: MBN and Ur were identified as
significant contributor towards soil health index (SHI). Deficit saline
irrigation (60WR) and ZT showed higher values of SHI. Thus, applying
deficit saline water irrigation, RT and mulching is most promising for
maintaining high SHI, saving fresh irrigation water without affecting
yield of RS-IW cropping system.