Maize dry matter yield and P uptake as influenced by rock phosphate and single super phosphate treated with farm manure.

Abstract

The availability of soluble P fertilizers at affordable prices has become a myth in Pakistan. One alternative under consideration is the use of locally available rock phosphate (RP) which requires dissolution of P from apatite before its use. The main aim of this study was to assess the availability of P from RP amended with farm manure (FM). Locally available rock phosphate and single superphosphate (SSP) as P2O5 were applied at 0+100, 25+75, 50+50, 75+25 and 100+0 %, respectively, with and without farm manure (10 tons ha -1 ) in addition to the treatment receiving recommended rate of N and K at 150 and 60 kg ha -1 in the form of urea and sulphate of potash, respectively. Farm manure application had a significant positive effect on plant growth, yield, P in leaf tissue and uptake of maize in all the treatments. The treatment receiving 25+75% RP and SSP along with 10 tons ha -1 FM produced maximum shoot dry matter yield (30 g pot -1 ), P content (0.31%) and uptake (0.10 g pot -1 ) followed by treatment having 50+50 RP and SSP . It may be concluded that RP integrated with SSP and FM increased maize growth, dry matter, leaf P content and uptake so, it can be adapted as an alternative strategy to get improved yield of maize in resource poor country like Pakistan.