Nutrient Absorption And Utilization Of Newly Bred Maize Hybrids With Slow Release Compound Fertilizers In Southwest Mountain Eco-region

Southwest mountain maize ecological area is one of the main maize producing areas in China.Its natural ecological and agricultural conditions are special and diverse.In addition to high yield and high quality,maize breeding should also emphasize the wide adaptability to environmental diversity.Slow release fertilizer is a new type of compound fertilizer whose nutrient release rate is basically consistent with the nutrient demand of crop growth.It can effectively save the labor cost of crop production when it is used as base fertilizer without topdressing.However,most of the previous reports about the single application of slow-release fertilizer as the base fertilizer to improve the yield and nutrient utilization rate of maize only compared the difference between the single application of various slow-release urea and common urea as the base fertilizer,and did not compare the difference between the single application of slow-release urea as the base fertilizer and the multiple application of common urea as the base fertilizer and top dressing.In a few of other comparison experiments usig slow-release compound fertilizers as base fertilizer,the ratio of nitrogen（N）,phosphorus（P）and potassium（K）was not in accordance with the absorption ratio and fertilizer requirement of maize.In the present study,two new hybrid varieties with wide adaptability to the southwest mountainous and hilly ecological region evaluated in regional experiment were planted in a split plot experiment with 3 replicates.A slow-release compound fertilizer with appropriative N,P,K content and release rate for maize growth was selected by nutrient extraction experiment,and used as base fertilizer,to compare with formula base fertilizer,and one base and three top dressing formula fertilizer with the same nutrient content.The yield of maize,rates of nutrient utilization,residue and loss were investigated and integrated as the supporting technology to meet the requirements of precise quantitative and light simplified cultivation of modern agriculture.The main results are as follows:（1）The nutrient content（N:P₂O₅:K₂O=20:8:12）and release rate of the WOFT compound fertilizer produced by Shandong Linyi WOFT compound fertilizer Co.,Ltd.basically conform to the nutrient demand and absorption law of maize growth.（2）No significant difference of yield was found between the one-time base fertilization of slow-release compound fertilizer and the one-time base fertilization and three top dressing of formula fertilizer.Howerver,the yield of these two treatments was significantly higher than that of one-time base formula fertilizer.Therefore,as long as the proportion of nitrogen,phosphorus and potassium is appropriate,the traditional fertilization of one base and three top dressing can also meet the requirement of maize growth.However,many times of top dressing operations increases labor input and does not meet the requirements of precise quantitative and light simplified cultivation of modern agriculture.（3）The yield（8084 kg/hm²）of Sanli 2178,bred by Guizhou Sanli Seed Industry Co.,Ltd.,under the condition of one-time base fertilization of slow-release compound fertilizer was significantly higher than the other eleven treatments between fertilizations×hybrids.This treatment combination was suggested as supporting technology for maize production in the hilly ecological area of Southwest China.（4）Variance analysis showed that the interaction between four fertilization levels and three hybrids was significant.Except for the low yield of non fertilization control and one-time formula base fertilization,the yield was high or low among the six treatment combinations between slow-release compound fertilizer,one base and three top dressing fertilization,and the three hybrids.This result indicated that different hybrids had different characteristics of fertilizer demand and nutrient absorption,and further production experiment was needed after regional experiment to compare yield effect of different technological treatments for dissemination.（5）The utilization ratio of N,P and K of the one-time base fertilization of slow-release compound fertilizer was the highest,the one-time base and three top dressing of formula fertilizer the second,and the one-time base fertilizeation of formula fertilizer the lowest.The residual rates of the one-time base fertilization of formula fertilizer was the lowest,the one-time base fertilization of slow-release compound fertilizer the second,and the one-time base and three top dressing of formula fertilizer the highest.The loss rate of the one-time base and three top dressing of formula fertilizer was the lowest,the one-time base fertilization of slow-release compound fertilizer the second,and the one-time base fertilization of formula fertilizer the highest.In conclusion,one-time base application of slow-release compound fertilizer with appositeness content,proportion and release rate of nitrogen,phosphorus and potassium for maize growth,combined with adaptive hybrids,can meet the requirements of accurate quantitative and light simplified cultivation of modern agriculture,reduce environmental pollution caused by nutrient loss,and be disseminated as supporting technology of maize production in the hilly ecological area of Southwest China.