04. Effect of city waste compost applied alone and in combination with chemical fertilizer on the yield and nutrient uptake of Wheat and subsequent Maize crop

The use of city waste as compost can provide a two way benefits of increasing soil productivity along with preventing pollution associated with population pressure, industrialization and urbanization. This study was conducted to determine the effect of the compost applied with chemical fertilizer, its effect on NPK uptake and nutrient use efficiency by wheat and maize plant. In this context, the effect of city waste compost at 10 and 20 tone ha-1 was evaluated along the application of half and ¾ of the recommended NPK doses on wheat crop and their residual effect on maize crop. The experimental design was RCBD with 3 replication for both crops under the same layout at Pirsabak Research Institute, Nowshehra. Commerical compost was applied and mixed with the soil a month prior to sowing. The phosphatic and potash fertilizer are applied in the form of SSP and SOP at time of sowing while the N fertilizer are applied in three split doses half at sowing time while the remaining with the first and second irrigation. In the succeeding reason, maize was sown in the same layout without applying any compost and chemical fertilizers to evaluate the residual effect of previously applied fertilizers. The CWC significantly improved both the wheat and residual maize thousand grain weight, grain yield and biological yield over alone NPK with maximum values for 20 t CWC ha-1 with 75 % NPK. The CWC also promoted the NPK status of soil and their uptake by wheat and residual maize suggesting that integration of CWC with NPK could improve the nutrient use efficiency and save the use of chemical fertilizer 25 to 50 %. The higher yield and superior performance of CWC in conjunction with NPK over sole NPK or control even in the residual maize advocated that the use of CWC could help in maintaining the soil productivity for the long run. These results suggested that the use of CWC will not only promote the agricultural productivity but could also help in safe disposal of the city wastes and could manage the current pollution scenario with increasing population pressure in urban areas of the country. Based the present study the application of 20 t ha-1 CWC with 75 % NPK could maintain higher yields of wheat and maize for two seasons under prevailing soil and climatic conditions. However, for wide spread application the CWC must be checked for contaminants like heavy metals and pathogens for safe handling and disposals to soils and preventing any hazardous effects on soil plant environment. Keywords: City waste compost; Urea; Single super phosphate; Sulphate of potash; Wheat; Maize http://dx.doi.org/10.19045/bspab.2015.44004