基于头季关键生育期的NDVI值诊断再生稻的生长状况

Diagnosis of Growth Status of Regenerated Rice Based on NDVI-value of Main Rice at Key Growth Stage

明确再生稻头季光谱数据与再生季生长的相关性,是一种预测和诊断再生稻生长状况的便捷方法。研究采取主动式的Greenseeker光谱仪,测定了不同再生稻品种(组合)关键生育期的NDVI,结合再生稻的生理指标分析计算了头季抽穗前后的NDVI和再生季抽穗后的干物质、LAI和叶片氮含量(累积)的相关性。结果表明头季抽穗后的NDVI与再生季抽穗后的绿叶生物量、LAI、营养器官和绿叶的氮累积具有显著的指数正相关,且不受再生稻品种(组合)类型的影响。利用不同密度试验的数据对方程进行了较充分的验证和检测,表明模拟值与实测值之间符合度较高,估算精度为0.9765,估计的RMSE为1.464,平均相对误差为-0.1191,RRMSE为0.1814。

To make clear the relationship between the growth of regenerated rice and the canopy NDVI value of main rice is a convenient method for forecasting and diagnosing the growth status of regenerated rice .This study measured the NDVI values of dif-ferent regenerated rice varieties （ combinations ） at key growth stages by using active spectrometer Greenseeker .Combining with the physiological indexes of regenerated rice , we analyzed and calculated the correlations of the NDVI of main rice before and after head-ing with the dry matter , LAI, and leaf nitrogen content （ accumulation ） of regenerated rice after heading .The results showed that there were significant positive correlations between the NDVI of main rice after heading and the green leaf biomass , LAI, and nitro-gen accumulation in vegetative organ and green leaf of regenerated rice after heading , and these correlations were not affected by the type of regenerated rice varieties （ combinations ） .These equations were adequately verified and detected by using the data of field experiments with different densities , and the results indicated that the degree of conformity was higher between the simulated values and measured values , the estimated accuracy was 0.9765, the estimated RMSE was 1.464, the average relative error was-0.1191, and RRMSE was 0.1814.