Enhancing Yield and Phosphorus Uptake of Canola Hybrids Through Integrated Use of Manure and Fertilizer Phosphorus.

Deficiency of P is of serious concern for agriculture productivity and limits crop production on > 90% of Pakistani soils. In addition, high pH and carbonate content in the soil may limit its utilization by plants. Use of manures in combination with fertilizer P and exploitation of differences among cultivars would be a promising strategy for increasing P use efficiency and the productivity of cropping systems. Investigations were conducted over two years in Pakistan to assess the effect of farmyard manure (FYM) and canola hybrids for improving P availability and uptake. We evaluated two canola hybrids (Hyola-401 and Hyola-43) and ten P management systems, which involved application rates and placement methods for fertilizer and FYM. The responses of growth, seed yield, components of yield, and quality were consistent during both years. Effects of canola hybrids and P management treatments varied significantly for leaf area index, crop growth rate, and net assimilation rate. Hyola-43 performed better than Hyola-401 for plant height, number of branches per plant, number of siliquae per plant, number of seeds per siliqua, 1000 seed weight, biomass yield, seed yield, straw P concentration, and seed P concentration. Treatments also affected quality parameters oil, protein, oleic acid, linoleic acid, and linolenic acid concentrations. All parameters were maximized by treatments involving 30 or 60 kg fertilizer P ha^-1 side-drilled along with side-dressed FYM. We concluded that by proper cultivar selection and integrated use of manure and fertilizer P, rates of P fertilizer can be reduced up to 50% thus sustaining the agriculture productivity and reducing environmental degradation.