Effects of organic manure and chemical fertilizer on soil fertility and productivity of plant and ratoon crops of sugarcane

A study was undertaken to evaluate the effects of integrated use of some organic manures and chemical fertilizers on soil fertility and productivity in plant and the subsequent ratoon crops of sugarcane. The manures included press mud, farmyard manure (FYM) and green manure (Crotalaria juncea) and the fertilizers were urea, TSP, MOP, gypsum and zinc sulphate. Application of organic manure in combination with chemical fertilizer increased absorption of N, P and K in cane leaf tissues both in the plant and ratoon crop as compared with chemical fertilizer alone. This led to higher cane and sugar yield of both crops. The maximum cane yield of 108.4 t ha − 1 and sugar yield of 9.47 t ha − 1 for the plant crop, and 96.8 t ha − 1 cane and 9.18 t ha − 1 sugar yields for the second crop (ratoon) were recorded where FYM at 15 t ha − 1 accompanied with chemical fertilizer (N178P53K54S26Zn2.6 kg ha − 1) were applied. The organic carbon, total N, and available P, K & S contents of soils increased slightly due to incorporation of organic manure. It appeared that 25% reduction of fertilizer application is possible if FYM or press mud at 15 t ha − 1 is used in plant and ratoon crops of sugarcane.