控释尿素氮素释放特征及其在番茄上的应用研究

应用室内恒温培养试验研究了释放曲线为抛物线型(L)和S型(S)的包膜控释尿素(L120d和S80d)在4种温度条件下(10、15、25、35℃)的氮素释放规律，并依托SUGIHARA和LOGISTIC模型探明了L120d和S80d氮素释放速率常数。在此基础上通过设施番茄试验，进一步验证了田间条件下控释氮素释放特征及其对番茄的效果影响。结果表明：室内培养条件下L120d和S80d氮素释放速率显著受温度影响，4种温度条件下释放速率常数分别为0.0022~0.0212/d和0.043~0.279/d，释放曲线分别呈现出抛物线型和S型特点。田间设施土壤条件下L120d氮素释放特征与之吻合，S80d释放周期差异达到30天以上，L120d和S80d氮素释放规律迥异。与普通尿素底施加3次追肥相比，施用L120d和S80d控释尿素的番茄产量较等氮量普通尿素(N 200 kg/hm2)和常规施氮量(N 400 kg/hm2)处理分别增加了7.8%、7.2%和5.4%、4.8%；氮素利用率提高了5.5~10.1个百分点；经济效益分别增加22817、13375元/hm2。此研究为控释肥料在设施农业上的应用和推广提供了科学依据。

Nitrogen Release Characteristic of Controlled-release Urea and Its Application Effect on Tomato

The nitrogen release characteristics of controlled release urea (L120d and S80d) whose shape of release curve was parabolic (L) and sigmoid (S) and release period was 120 d and 80 d respectively were studied by constant temperature incubation experiment, the release rates (k) were obtained according to SUGIHARA and LOGISTIC models. On the basis of facility tomato experiment, a field experiment was carried out to study the characteristic of nitrogen release and its effect on tomato. The results showed that the k values of L120d and S80d were significantly affected by temperature under indoor culture conditions, k values were 0.0022~0.0212/d and 0.043~0.279/d respectively under 4 kinds of temperature conditions, the release curve showed the characteristics of L and S types respectively. The characteristics of L120d in field experiment wasconsistent with indoor culture conditions, but the release period of S80d in field condition had the difference of more than 30 d, the nitrogen release characteristic of L120d and S80d was different. Compared with urea basal application and 3 topdressings, tomato yield of L120d and S80d increased by 7.8%, 7.2% and 5.4%, 4.8% in comparing with that of common urea (N 200 kg/hm2) and conventional N rate (N 400 kg/hm2); nitrogen use efficiency (NUE) increased by 5.5-10.1 percentage point, and the economic benefits increased by 22817 and 13375 yuan/hm2. This study provided a scientific basis for the popularization and application of controlledrelease fertilizer in facility agriculture.