Growth Metabolism And Canopy Spectral Characteristics Of Corn Under Different Fertilization

The test applied the integrated research method of field experiment and laboratory analysis on the directive breeding soil five years location test with different fertilization treatments, and study the effects on yield, quality, nitrogen metabolism, active oxygen metabolism and canopy spectral characteristics of corn under different fertilization, and to investigate the correlation between the corn canopy spectral vegetation index and yield, nitrogen metabolism key enzyme activity to better using canopy spectral real-time monitoring of corn growth, increasing grain yield and quality. The main results are as follows:1 The treatment of NPK was the highest grain yield, followed by NP, compared to the blank were increased by 63.30% and 55.35%, and the yield component factors have significant promoting effect, ear weight, grain number per ear and 1000 grain weight of NPK treatment were significantly higher than those of other treatments and NPK treatment of filling rate is the highest. The total protein content, total soluble sugar content and gross fat content of NPK and NP treatments were significantly higher than those of other treatments, and the protein showed significant “dilution effect”.2 The N 、 P2O5 and K2 O nutrient uptake of corn straw and grain showed NPK>NP>NK>PK>CK, the nitrogen harvest index and physiological efficiency instead of total uptake; The phosphorus harvest index of CK and NP treatments were lower than others, but the physiological efficiency were higher; The potassium harvest index of NP and CK were higher, absorption of potassium known as more assigned to grain, the physiological efficiency was higher.3 The fertilization has significant promoting effect on physiological metabolism of ear leaf, The treatment of NPK in content of chlorophyll, photosynthetic rate, transpiration rate, key enzymes activities of nitrogen metabolism and active oxygen metabolism were the highest, the lowest in the treatment of CK.4 In different periods, the canopy reflectance spectral of corn on different fertilization treatment was different. But the trend was basically consistent, a "green" peak appeared in about 550 nm, reflectance increased sharply after the 700 nm, to near infrared high about 750 nm, this band canopy spectral reflectance from high to low in order to NPK>NP>NK>CK>PK, 28 d after silking,the three canopy spectral curves(NP, NK,CK) tended to overlap.5 In different periods,the correlation cefficient of vegetation index SAVI and yield reached significant level, the 14 d after spinning, the fitting equation of vegetation index SAVI and the yield was Y=12704.892+12429.966 lnX, R2 value was 0.991, F value was 326.730, reaching 0.1%significant level.6 In different periods,the correlation cefficient of vegetation index and the activity of nitrogen metabolism reached significant level,The 14 d after spinning, the fitting equation of vegetation index SAVI and the activity of NR was Y=-26.768+59.465X-35.595X3; the 0d after spinning, the correlation between vegetation index PRI and the activity of GDH showed significantly negative correlation, the fitting equation was Y=0.257-3.491X; The 28 d after spinning, the fitting equation of vegetation index SDr and the activity of GS wasY=0.149e4.138 X.