Effects of nitrogen and phosphorus fertilizer on corn growth and fertilizer use.

To explore the effect of fertilization in low-yielding fields in the dry hilly areas on soil fertility and corn yield,the experiment of nitrogen(0,90,180,270,360 kg/ha)and phosphorus(0,135 kg/ha)fertilization was carried out in dry hillock in Yuzhou of Henan province.The results showed that the growth and development of corn could be improved by rational nitrogen and phosphorus ratio.Plant height increased with increasing nitrogen application under single nitrogen condition,and got to the highest at 180 kg/ha of nitrogen.The panicle length,effective panicle length,grains and grain-stem ratio reached maximum at 270 kg/ha of nitrogen.When 135 kg/ha of P2O5 was combined,the plant height and panicle length increased with nitrogen application increased.The panicle location,effective panicle length,100-grain weight and the grain number had the highest at 270 kg/ha of nitrogen.The phosphorus treatments improved the development of corn obviously compared to the corresponding treatment with no phosphorus.The plant height,the effective panicle length,the 100-grain weight and the grain number per ear increased by 3-10 cm,0.26-0.45 cm,0.5-3.0 g,8.8-39.8 grains,respectively.The average yield increased by 5.81%-36.88% compared with the P0N0 treatment,and the best one was the P135N270 treatment.Under no phosphorus application,the yield increased by 5.81%-25.23% with the amount of nitrogen increased,with the P0N360 treatment the best.After 135 kg/ha of P2O5 was added,the production increased with nitrogen application increased,and got to the highest at N270,increased by 21.56%.The yield of phosphorus treatments increased by 6.21%-13.77% compared to that of the corresponding treatment with no phosphate,and the best one was P135N90.According to the set production target of 8 700 kg/ha,the amount of nitrogen fertilizer was at least 270 kg/ha without phosphate application,while the nitrogen requirement was only 180 kg/ha when 135 kg/ha of P2O5 was applied.The efficiency of nitrogen utilization decreased with the increase of nitrogen applied,but the efficiency of phosphorus utilization increased,and reached the highest at P135N270.Meanwhile,the organic matter in cultivated soil was increased by 0.2-2.2 g/kg.The available phosphorus under phosphorus treatments was increased by 0.50-1.75 g/kg,and it reduced by 0.25-1.07 g/kg without phosphate.The content of hydrolysis nitrogen under nitrogen treatments was increased by 3.3-16.2 mg/kg.Therefore,corn required fertilization with reasonable phosphate and potassium fertilizer under the condition of nitrogen application in order to obtain high yield and profit.