Fertilizer-Liking Grade Of Maize And Its Balanced Control For NPK

Jilin Province is the main grain production area of china whose per unit area yield is the largest in the whole china and maize production is increasingly important to the whole china, rational fertilizer use is very important on stable maize yield ,reduce maize production cost and increase production profit. Many problems still exit on maize fertilizer application .one of the main reason is that people can not determine the fertilizer use amounts according to fertilizer absorption ability and fertilizer-liking characteristics between maize varieties. which lead to not only maize yield reduction but also chemical fertilizer waste and loss and environment pollution. Aiming at the above problems, through research on the representative 37 maize varieties using field experiment and plant analysis , the following results were obtained:1 the maize that had weak nutrient absorption ability to soil usually had strong nutrient absorption ability to chemical fertilizer. There are great difference on N,P,K absorption amounts between different maize varieties . Difference on the utilization rate of the same amounts fertilizer to different maize varieties reached 27% between the highest and the lowest .Yield increase effects and economic benefits of the same amount chemical fertilizer to different maize varieties reached 3859 kg/ha and 3859yuan/ha between the highest and the lowest. So we can see that effect on chemical fertilizer result from difference on fertilizer absorption ability between maize varieties far exceed difference on the fertilizer application technique.2 Classification standards for maize fertilizer absorption parameters and maize fertilizer absorption ability. According to the actual condition of agricultural production and using fertilizer absorption parameters , the experimental maize were divided into three grades.Classification standards for N absorption ability of maize : high> 1. 80, middle1. 0 -1. 80,low <1. 0Classification standards for P₂O₅ absorption ability of maize :high > 0. 9 ,middle0. 3- 0. 9, low < 0. 3Classification standards for K₂O absorption ability of maize :high> 1.50 ,middle0. 8- 1.5, low <0. 8Classification standards for NPK absorption ability of maize :high > 1.20, middle0. 7 - 1. 2, low < 0. 73 Classifications of fertilizer -liking extent for maize and its standards Classifications Standards for low fertilize-liking extent maize were that effectparameters of chemical fertilizer were ^O. 40.Classifications Standards for middle fertilize-liking extent maize were that effect parameters of chemical fertilizer were 0. 41-0. 90.Classifications Standards for high fertilize-liking extent maize were that effect parameters of chemical fertilizer were>0. 90.4 Economic fertilizer application amounts and the maximum yield fertilizer application for the three fertilizer susceptible maize of high, middle and low and their appropriate average value variation range.The maximum yield N fertilizer application ,P fertilizer application and K fertilizer application is 270 ± 25kg/ha, 85 ± 20kg/ha andllO ± 20kg/ha respectively for the high fertilizer susceptible maize .The economic yield N fertilizer application ,P fertilizer application and K fertilizer application is 225 ± 25kg/ha, 85±20kg/ha and 90±20kg/ha respectively for the high fertilizer susceptible maize .The maximum yield N fertilizer application ,P fertilizer application and K fertilizer application is 225 ± 25kg/ha, 70±20kg/ha and 90±20kg/ha respectively for the middle fertilizer susceptible maize.The economic yield N fertilizer application ,P fertilizer application and K fertilizer application is 190 ± 20kg/ha, 85 + 20kg/ha and 90 ± 20kg/ha respectively for the middle fertilizer susceptible maize.The maximum yield N fertilizer application ,P fertilizer application and K fertilizer application is 210 ± 25kg/ha, 75 ± 20kg/ha and80 + 20kg/ha respectively for the low fertilizer susceptible maize.The maximum yield N fertilizer application ,P fertilizer application and K fertilizer application is 165 ± 25kg/ha, 60 ± 20kg/ha and 70 ± 20kg/ha respectively for the low fertilizer susceptible maize.5 Using economic fertilizer application for middle and low fertilizer requirement maize can save a large quantity of chemical fertilizer and money, if this technique was popularize in the whole province N fertilizer could be saved by 289 thousand tons , P fertilize could be saved by 126 thousand tons and money can be saved by 262 million yuan. At the same time , the utilization rate of chemical fertilizer can be increased in a bigrange . Utilization rate of N fertilizer and K fertilizer for high fertilizer requirement maize could be increased by 3%-ll% and 3%-26% respectively, for middle fertilizer requirement maize can be increased by 5.7%-19.6% and 3%-33.5% respectively, or low fertilize requirement maize can be increased by 6%-17.6% and 4.4%-28.1%. Utilization rate of P fertilizer for the three fertilizer susceptible grades of maize could be increased by...