A novel approach for increasing productivity under precision nitrogen management in maize (Zea mays L.) through crop sensors

Global maize production reached 1075 million tons in 2016, according to the FAO database. While maize is considered as staple food for many populations across the globe, increasing the productivity using crop sensors like SPAD chlorophyll meter and GreenSeeker meter in maize could be a effective tool to achieve sustainable developmental goal- end hunger and secure food security. The current approaches to detect soil and plant N levels are soil-testing, visual diagnosis and foliar analysis. However, these conventional approaches are time consuming, expensive; require considerable effort for soil collection or plant sampling, processing and results are not immediately available. Therefore, to provide appropriate recommendations of spatial N applications, it is necessary to use several tools simultaneously, such as crop and soil sensors, to achieve reliable measurements of N availability from soil and crops need. The result showed in pooled data of 2016 and 2017, increased growth parameters (viz., plant height, number of green leaves, leaf area, dry matter production and SPAD chlorophyll readings) and yield parameters (viz., number of cobs per plant, cob length and girth, kernels per row, kernels per cob, grain yield and stover yield) recorded in STCR based NPK management for target of 11 t ha-1. However, the nitrogen use efficiency was registered in highest in N management through SPAD-40, N25, but recovery use efficiency, agronomic efficiency and physiological efficiency were higher under GreenSeeker based nitrogen management (NDVI values).