Influence of Irrigation Regimes, Zeolite, Inorganic and Organic Manures on Water Use Efficiency, Soil Fertility and Yield of Sunflower in a Sandy Soil
Abolfazl Baghbani-Arani, Mohammad Ghasem Jami, Amin Namdari, Rezvan Karami Borz-Abad
Abstract
Sandy soils provide suitable physical conditions for sunflower growth, yet the limited capacity to retain water and nutrients is the main problem in these soils and innovative strategies are needed to cope with these limitations. In this regard, a study was carried out as split-factorial experiment in a sandy soil in semi-arid region of Iran for two years (2014 and 2015). Three irrigation regimes including irrigation after depleting 40%, 60% and 80% (I1, I2 and I3) of available soil water (ASW) were considered as main plots. The sub-plots consisted of factorial combinations of three nitrogen fertilizer treatments (F1: 100% organic, F2: integrated treatment and F3: 100% chemical treatment) and three levels of zeolite (10, 5 and 0 ton ha−1). The organic and chemical sources of nitrogen were respectively manure farmyard and urea, and integrated treatment included 50% organic + 50% chemical nitrogen. The results showed that water deficit caused a considerable decrease in agronomic performance, productivity, water use efficiency (WUE), grain’s oil and protein concentration. In most treatments, both manure farmyard and zeolite application increased chlorophyll content (SPAD), biological yield, grain yield and oil, protein concentration within sunflower’s grain. Regardless of the irrigation regime, the highest oil concentrations were achieved by applying integrated treatment accompanied by 10 ton ha−1 zeolite. The results demonstrated that using manure farmyard (either 100% or 50%) accompanied by zeolite as input caused significant improvement in WUE. The improvement in WUE resulted from higher grain yield due to implementing organic nutrition and amending soil with zeolite.