Agronomic Effectiveness and Phosphorus Utilization Efficiency of Rock Phosphate Applied to Winter Wheat

Abstract

Rock phosphate (RP) is an important natural source of P for plant nutrition, but the solubility and availability of P from RP is an issue in agricultural production systems. Integrated use of RP with various organic and inorganic byproducts has been reported to increase RP P use efficiency and stability of crop yields. A 2‐yr (2010–2011 and 2011–2012) field experiment was conducted to examine the agronomic effectiveness and P utilization efficiency (PUE) of RP supplemented with wood ash, compost, and poultry manure with and without phosphate‐solubilizing bacteria applied to rainfed wheat (Triticum aestivum L.) in the hilly region of Kashmir, Pakistan. The experiment was conducted in a completely randomized block design with factorial arrangement using three replications. Treatments included: control; RP; RP + wood ash (WA); RP + poultry manure (PM); RP + compost; control + phosphate‐solubilizing bacteria (PSB); RP + PSB; RP + WA + PSB; RP + PM + PSB; and RP + compost + PSB. Results indicated that RP alone did not show significant effects on growth and PUE of wheat; however, the use of RP with PM and compost improved straw yield (21 and 22%), grain yield (52 and 50%), plant P uptake (73 and 84%), and PUE (95 and 103%) over the RP alone. Also RP + PM and RP + compost, when inoculated with PSB, resulted in a further increase in yield of 9 and 8%, P uptake of 28 and 29%, and PUE of 35 and 42%, respectively. These results demonstrate that use of PSB and organic amendments with RP could be a promising management strategy and viable technology to utilize both low‐grade RP and organic materials efficiently for crop production and nutrient improvement in mountainous ecosystems.