Application of rock phosphate enriched composts increases nodulation, growth and yield of chickpea

Purpose Phosphorus (P) defciency in agricultural land is one of the main factors which reduce the crop production and yield. To increase the crop growth, the availability of P using the rock phosphate (RP) can be enhanced using organic waste with the addition of phosphate solubilizing microorganisms (PSMs). Moreover, the combination along with time and dose application of RP and compost can also afect the P-availability through mineralization and/immobilization. Methods To investigate the efect of diferent combinations of RP and compost (۰:۱۰۰, ۲۵:۷۵, ۵۰:۵۰, ۷۵:۲۵ and ۱۰۰:۰) and time of application (۳۰, ۱۵, ۷, ۳ and ۰ days before sowing), each was conducted in two consecutive pot experiments while, the rate of application (۱۰۰–۱۰۰۰ kg ha−۱) was investigated under feld conditions, in comparison to control (recommended P fertilizer). Results Rock phosphate enriched compost (RP-EC) with a combination ratio of ۵۰:۵۰; RP and compost applied before ۷ days of sowing in pot experiments resulted in the maximum nodulation, growth and productivity of chickpea. Under feld conditions, the maximum increase of ۳۵.۳% in no. nodules plant−۱, ۲۶.۷% in dry wt. of nodules plant−۱ and ۲۰.۸% in grain yield (t ha−۱) compared to control was obtained by RP-EC @ ۱۰۰۰ kg ha−۱. The same treatment indicated an increase of ۱۲.۹ and ۴.۳% in P contents in straw and grains, respectively, compared to control. However, most results were non-signifcant when RP-EC applied at the rate of ۱۰۰۰ kg ha−۱. Conclusion Application of RP-EC, with the ratio of ۵۰:۵۰ (RP:Compost) and application rate of ۸۰۰ kg ha−۱ before ۷ days of sowing, exhibited maximum growth and development, and can be highly recommended for optimum production of chickpea.