基于近地光谱探测技术的冬小麦变量施肥

Variable-rate fertilizing for winter wheat based on canopy spectral reflectance

首先利用GreenSeeker RT200变量施肥机器系统按小区测量了田间试验区冬小麦在拔节期的归一化植被指数NDVI,然后根据改进的氮肥优化算法,由测得的NDVI数据和预测的谷物可能产量等参数,计算出氮肥需要量FNR,进而根据不同小区的氮肥需要量进行了田间变量施肥。试验结果表明,采用变量施肥之后,冬小麦的NDVI空间变异明显变小,作物长势趋于平衡。对比常规管理区和精准管理区的产量分布,精准管理区的产量不仅空间变异小,而且产量明显提高。

Variable-rate Fertilizing （VRF） for winter wheat was attempted with the support of groundbased sensing. First, the Normalized Difference Vegetation Index （NDVI） of winter wheat in elongating stage was measured using a variable rate fertilizer, GreenSeeker RT200. Then using nitrogen fertilization optimization algorithm, the different fertilizer nitrogen rates （FNR） used in different experiment zones were calculated based on the in-season estimation of yield and the plant nitrogen uptake in different zones. Finally, VRF was conducted according to FNR. Experiments show that, with VRF, the spatial variation of NDVI of winter wheat becomes obviously smaller comparing with that without VRF, the plant tends to balance growth and the yield obviously increases.