| Waxy corn (Zea mays L.ceretina Kuiesh) is one of the new crop varieties that cultivated widely in Hainan recently years, but low yield due to extentive management. In order to understand the nutrition regulation of waxy com, the characteristics of fertilizer requirement and then make out appropriate measures, two field experiments were conducted to study the the content, uptake and distribution of nitrogen, phosphorus and potassium and the effects of nitrogen, phosphorus, potassium and population density on yield, protein content, starch content and soluble sugar content with saturated D-optimal design for quadratic regression in waxy com. The results showed as follow:1. The relative absorption of nitrogen amount in seeding stage, jointing stage, small bell mouth stage, big bell mouth stage, tassel emerge, filling stage, wax ripeness and complete ripeness were 1.85, 5.49, 22.26, 23.69, 16.24, 19.58, 7.17 and 3.73%, respectively.Before tassel emerge, the nitrogen amount was mainly distributed in leaves and followed by stem and sheath with 45.16, 33.16 and 11.01%, totally 89.33%, respectively. Then it was transferred into grain, hull cob and tassel gradually by growth. Nitrogen distributed 64.09% in grain and 30.76% only in leaves, stem and sheath at wax ripeness stage.Nitrogen sources in grain of wax com were 51.25% come from vegetative organ, while 48.75% come from root uptake.2. The relative absorption of phosphorus amount in seeding stage, jointing stage, small bell mouth stage, big bell mouth stage, tassel emerge, filling stage, wax ripeness and complete ripeness were 0.89, 5.07, 23.99, 29.90, 10.10, 12.42, 10.81 and 6.82%, respectively.Before tassel emerge, the phosphorus amount was mainly distributed in leaves and followed by stem and sheath with 37.70, 34.32,17.76%, totally 89.78%, respectively. Then it was transferred into grain, hull cob and tassel gradually by growth. Phosphorus was distributed 62.69% in grain and 32.42% only in leaves, stem and sheath at wax ripeness stage.Phosphorus sources in grain of wax corn were 51.70% come from vegetative organ, while 48.30 % come from root uptake.3. The relative absorption of potassium amount was in seeding stage, jointing stage, small bell mouth stage, big bell mouth stage, tassel emerge and filling stage were 0.12, 3.49, 14.70, 26.84, 23.69 and 15.58%, respectively.Before tassel emerge, the potassium amount mainly distributed in leaves and followed by stem and sheath with 38.28, 29.19, 19.48%, totally 86.95%, respectively. Then it was transferred into grain, hull cob and tassel gradually by growth. Potassium distributed 27.61% in grain and 72.39% only in leaves, stem and sheath at wax ripeness stage, but potassium will inverse flow to vegetative organ, which rise to 76.82% in wax ripeness.4. The ratio of N, P2O5, K2O was different in each stage of waxy corn. The maximum absorption of nutrient amount was nitrogen, followed by potassium, and phosphorus. In the whole life cycle, the ratio of N, P2O5, K2O was 1:0.41:0.62. The quantity of N, P2O5, K2O needed for producing 100 kg of grain was 2.11,0.87 and 1.31 kg, respectively.5. The yield of waxy corn was mostly affected by population density and nitrogen but potassium and phosphorus was minor relatively. The yield would be increased by each factor under proper range, but decreased beyond the best level. The best combination for obtaining maximum yield was N 203.24 kg/hm2, P2O5 101.66 kg/hm2, K2O 126.51 kg/hm2, population density 59264.24plant/hm2, which theoretic yield was 12387.73 kg/hm2.The best combination for obtaining maximum economic yield was N 203.40 kg/hm2, P2O5 100.96 kg/hm2, K2O 126.68 kg/hm2. In the other word , the cost of N, P2O5, K2O was 707.832 yuan/hm2, 336.197 yuan/hm2, 358.504 yuan/hm2, respectively, the theoretic yield was 12384.40 kg/hm , and output value was 24768.8 yuan/hm , while profit was 23366.267 yuan/hm2.6. The protein content of waxy corn was mostly affected by nitrogen, while nitrogen, population density and potassium was almost indifferent, while phosphorus was minor relatively. The design application which gain maximum protein content of waxy corn was N 237.15 kg/hm2, P2O5 97.06 kg/hm2, K2O 116.96 kg/hm2, population density 60697.75 plant/hm2, and theoretic protein content was 12.129 %.7. The starch content of waxy corn was mostly affected by phosphorus, potassium was second, while nitrogen and population density was minor relatively. The best combination for obtaining maximum starch content of waxy corn was N 308.7003 kg/hm2, P2O5 200.0048 kg/hm2, K2O 201.7052 kg/hm2, population density 40000 plant/hm2, which...
|
PDF Full Text Request