Combined application of chemical fertilizers, organics and foliar spray of zinc and iron on yield, quality and water productivity of aerobically grown rice (Oryza sativa) in calcareous soil

Abstract

Increasing multi-nutrient deficiencies and water scarcity is a major challenge for rice cultivation. In calcareous soils, nitrogen (N), iron (Fe) and zinc (Zn) deficiencies are major constraints for aerobically grown rice. Thus, a field study was conducted in factorial randomized block design with 18 treatment combinations viz. 75% recommended dose of nitrogen (RDN) through chemical nutrient source and 25% RDN through of organic sources (vermicompost or poultry manure or farm yard manure) and foliar spray with Zn and Fe at tillering and panicle initiation stage. All the growth related traits, yield attributes, yield and nutrient uptake were significantly influenced by nutrient management practices. On an average, mean grain yield was improved by 28.5% with the application of 100% RDN through chemical fertilizers + 25% RDN through vermicompost over alone 100% RDN through chemical fertilizer. Higher nitrogen uptake (100.4 kg ha−1), phosphorous (14.7 kg ha−1), potassium (95.9 kg ha−1), iron (1085.1 g ha−1) and zinc (295.1 g ha−1) were also recorded with same treatment. Application of 75% RDN through chemical fertilizer + 25% RDN through poultry manure recorded significantly higher water productivity of 0.130 US$/m3 than all other treatments while application with 100% RDN through chemical fertilizers recorded lowest water productivity of 0.091 US$/m3. The present finding indicates that under current situation of declining water resources and increasing multi-nutrient deficiencies, combined application of chemical fertilizers and poultry manure along with foliar spray of Zn and Fe will enhance the quality produce, and water productivity in aerobically grown rice in calcareous soils.