Quebrajo Lucía, Pérez-Ruiz Manuel, Rodriguez-Lizana Antonio, Agüera Juan
Aerospace Engineering and Fluids Mechanics Department, University of Seville, Ctra. Sevilla-Utrera km. 1, Seville 41013, Spain.
Rural Engineering Department, University of Cordoba, Córdoba 14071, Spain.
Sensors (Basel). 2015 Mar 6;15(3):5504-17. doi: 10.3390/s150305504.
Regardless of the crop production system, nutrients inputs must be controlled at or below a certain economic threshold to achieve an acceptable level of profitability. The use of management zones and variable-rate fertilizer applications is gaining popularity in precision agriculture. Many researchers have evaluated the application of final yield maps and geo-referenced geophysical measurements (e.g., apparent soil electrical conductivity-ECa) as a method of establishing relatively homogeneous management zones within the same plot. Yield estimation models based on crop conditions at certain growth stages, soil nutrient statuses, agronomic factors, moisture statuses, and weed/pest pressures are a primary goal in precision agriculture. This study attempted to achieve the following objectives: (1) to investigate the potential for predicting winter wheat yields using vegetation measurements (the Normalized Difference Vegetation Index-NDVI) at the beginning of the season, thereby allowing for a yield response to nitrogen (N) fertilizer; and (2) evaluate the feasibility of using inexpensive optical sensor measurements in a Mediterranean environment. A field experiment was conducted in two commercial wheat fields near Seville, in southwestern Spain. Yield data were collected at harvest using a yield monitoring system (RDS Ceres II-volumetric meter) installed on a combine. Wheat yield and NDVI values of 3498 ± 481 kg ha(-1) and 0.67 ± 0.04 nm nm(-1) (field 1) and 3221 ± 531 kg ha(-1) and 0.68 ± 0.05 nm nm(-1) (field 2) were obtained. In both fields, the yield and NDVI exhibited a strong Pearson correlation, with r(xy) = 0.64 and p < 10(-4) in field 1 and r(xy) = 0.78 and p < 10(-4) in field 2. The preliminary results indicate that hand-held crop sensor-based N management can be applied to wheat production in Spain and has the potential to increase agronomic N-use efficiency on a long-term basis.
无论作物生产系统如何，养分投入必须控制在一定经济阈值或以下，以实现可接受的盈利水平。管理分区和变量施肥在精准农业中越来越受欢迎。许多研究人员评估了利用最终产量图和地理参考地球物理测量（如土壤表观电导率-ECa）作为在同一地块内建立相对均匀管理分区的方法。基于作物特定生长阶段的状况、土壤养分状况、农艺因素、水分状况以及杂草/害虫压力的产量估算模型是精准农业的主要目标。本研究试图实现以下目标：（1）研究在季节开始时使用植被测量（归一化差异植被指数-NDVI）预测冬小麦产量的潜力，从而实现对氮肥（N）的产量响应；（2）评估在地中海环境中使用廉价光学传感器测量的可行性。在西班牙西南部塞维利亚附近的两个商业小麦田进行了田间试验。收获时使用安装在联合收割机上的产量监测系统（RDS Ceres II-容积计）收集产量数据。获得了小麦产量和NDVI值，分别为3498±481 kg ha(-1)和0.67±0.04 nm nm(-1)（第1块田）以及3221±531 kg ha(-1)和0.68±0.05 nm nm(-1)（第2块田）。在两块田中，产量和NDVI均呈现出很强的皮尔逊相关性，第1块田r(xy)=0.64且p<10(-4)，第2块田r(xy)=0.78且p<10(-4)。初步结果表明，基于手持式作物传感器的氮素管理可应用于西班牙的小麦生产，并且从长期来看有提高农学氮素利用效率的潜力。
