Effects of emitter discharge rates on soil salinity distribution and cotton (Gossypium hirsutum L.) yield under drip irrigation with plastic mulch in an arid region of Northwest China

Abstract

A field experiment was carried out to investigate the effects of different emitter discharge rates under drip irrigation on soil salinity distribution and cotton yield in an extreme arid region of Tarim River catchment in Northwest China. Four treatments of emitter discharge rates, i.e. 1.8, 2.2, 2.6 and 3.2 L/h, were designed under drip irrigation with plastic mulch in this paper. The salt distribution in the range of 70-cm horizontal distance and 100-cm vertical distance from the emitter was measured and analyzed during the cotton growing season. The soil salinity is expressed in terms of electrical conductivity (dS/m) of the saturated soil extract (EC e), which was measured using Time Domain Reflector (TDR) 20 times a year, including 5 irrigation events and 4 measured times before/after an irrigation event. All the treatments were repeated 3 times. The groundwater depth was observed by SEBA MDS Dipper 3 automatically at three experimental sites. The results showed that the order of reduction in averaged soil salinity was 2.6 L/h > 2.2 L/h > 1.8 L/h > 3.2 L/h after the completion of irrigation for the 3-year cotton growing season. Therefore, the choice of emitter discharge rate is considerably important in arid silt loam. Usually, the ideal emitter discharge rate is 2.4-3.0 L/h for soil desalinization with plastic mulch, which is advisable mainly because of the favorable salt leaching of silt loam and the climatic conditions in the studied arid area. Maximum cotton yield was achieved at the emitter discharge rate of 2.6 L/h under drip irrigation with plastic mulch in silty soil at the study site. Hence, the emitter discharge rate of 2.6 L/h is recommended for drip irrigation with plastic mulch applied in silty soil in arid regions.

Water Use Efficiency in Saline Soils under Cotton Cultivation in the Tarim River Basin

“…The irrigation type [60], irrigation rate [46] and the irrigation amount [10] have effected on the cotton yield. Especially, Soil salinity and sodicity can be maintained at acceptable low levels by appropriate preplant irrigation [61].…”

The soil–water flow system beneath a cotton field in arid north-west China, serviced by mulched drip irrigation using brackish water

“…Water shortage and soil salinization are the two critical problems affecting sustainability of the agriculture in arid regions (Chen et al 2010a;Danierhan et al 2013). Over 50 % of river water is developed for the purposes of irrigation in Xinjiang, north-west China, and more than 70 % of the developed rivers are inland (Li 2003).…”

“…Treatments with and without plastic mulch have significant effects on soil water and salinity distribution (Selim et al 2013;Kirnak and Demirtas 2006). The wetting patterns of drip irrigation depend on several factors including the drip-line and dripper placement, soil texture, root-water uptake, irrigation intensity, and initial water content (Cook et al 2003;Kirnak and Demirtas 2006;Zumr et al 2006;Hao et al 2007;Shan et al 2011;Danierhan et al 2013;Wang et al 2014b). Bar-Yosef and Sheikholslami (1976) found that the soil water was prone to expanding in the vertical profile of sandy soil under drip irrigation.…”

“…Bar-Yosef and Sheikholslami (1976) found that the soil water was prone to expanding in the vertical profile of sandy soil under drip irrigation. Danierhan et al 2013 investigated the effects of different dripper discharge rates on salinity distribution. After drip irrigation in experiments for 3 and 7 years, Zhang et al (2013) found that salts got accumulated within 0-40 and 40-80 cm depths of soil layers respectively, when drainage systems were incomplete.…”

Plastic mulching with drip irrigation increases soil carbon stocks of natrargid soils in arid areas of northwestern China

“…Plastic film mulching cultivation (PC) with drip irrigation has been promoted as a sound agricultural practice designed to improve the efficiency of use of soil nutrients by crops, and to improve the photosynthetic capacity and yield of crops (Danierhan et al, 2013;Dong et al, 2008;Liang et al, 2013). This type of cultivation is now widely applied in China (Li et al, 2004), including 1,000,000 ha in northwestern China in 2009 (Gu et al, 2012).…”