Mulches Improve Ridge‐tillage Tomato Production under Drip Irrigation with Saline Water

Abstract

Core Ideas Soil salinity three years after first growing season was fluctuated slightly.Soil salinity under wheat straw was lower than both waterproof and pervious plastic mulch.Wheat straw improved tomato yield, followed by black waterproof plastic mulch. Fresh water resources in the North China Plain are declining due to increasing industrial and domestic water use. These uses raise the agricultural demand for low quality water. To provide appropriate management techniques for safely using saline water, different mulching materials were tested on ridge‐tillage tomato (Lycopersicon esculentum Mill.). Four treatments: control (bare land, CK), black plastic (BPM), black sheet net (BSN), and wheat straw (SM) were designed to: (i) evaluate the effects of mulching on the irrigation amount, soil salinity, tomato yield, and irrigation water productivity (IWP); and (ii) develop integrated irrigation strategies using saline water securely. The average required water for the SM and BPM treatments reduced by 12 and 20%, respectively. Electrical conductivity of saturated paste extracts (ECe) increased from 1.91 to 4.07 dS m−1 in 0‐ to 40‐cm root zone and from 2.33 to 4.24 dS m−1 in 0‐ to 120‐cm soil profile after the first year irrigation, and then fluctuated slightly during the next 3 yr due to precipitation and evaporation. The ECe for the SM treatment was always the least in 4 yr. Compared with CK, the BPM and SM treatments over 4 yr increased the average tomato yield by 26 and 42%, and increased the average IWP by 62 and 70%, respectively. Therefore, straw mulching was the best mulching material to safely use saline water of <6.3 dS m−1 for the ridge‐tillage tomato under drip irrigation, followed by black plastic mulching, in a temperate semi humid monsoon climate zone.