Nitrogen fertilization management in white oat using spectral indices

Abstract

Remote sensing techniques have been considered a new technology in worldwide agriculture for diagnosing the plant nutritional demand. Fertilizer management efficiency is a goal to be achieved, and modern tools based on remote sensing are promising for monitoring the crop needs. This study aimed to evaluate the agronomic performance and relative economic return of white oat under nitrogen rates, as well as to verify whether the normalized difference vegetation index (NDVI) and leaf chlorophyll index (LCI) could be used for topdressing nitrogen fertilization management, in white oat. Treatments consisted of five topdressing nitrogen fertilization strategies: T1 - 160 kg ha-1 (reference rate); T2 - 90 kg ha-1 (recommended rate); T3 - 60 kg ha-1 (economic rate); T4 - 30 kg ha-1 (when NDVI < 90 % of T1); and T5 - 30 kg ha-1 (when LCI < 90 % of T1). The white oat did not respond to the topdressing nitrogen fertilization. Its temporal monitoring using spectral indices allowed dispensing the topdressing nitrogen fertilization without reducing the grain and biomass yields and the leaf nitrogen content, when compared to the recommended management (90 kg ha-1 of N as topdressing), with no differences between the evaluated spectral indices. Thus, both the NDVI and LCI spectral indices are promising tools for the topdressing nitrogen fertilization management in the white oat crop.

Use of machine learning for monitoring the growth stages of an agricultural crop

“…An important aspect of soil health management is the timely and appropriate application of fertilisers to ensure favourable nutrient conditions to maximise crop yield and thereby contribute to global food security. 12,13 Determination of temporal and spatial patterns of crop growth are critical for assessing fertiliser application. In many instances, the crop nitrogen status is estimated indirectly from the variables of chlorophyll content and the leaf area index as can be done using a hand-held chlorophyll meter.…”

Effect of Timing and Dosage of “Kas 28” Application on Oat Plants Development

“…Данные, полученные в работах зарубежных ученых [12,13] показывают, что в благоприятный по метеорологическим условиям год внекорневые подкормки эффективнее применять на 40-45 день после всходов, а в неблагоприятный год -на 30-35 день после всходов. Таким образом, правильное использование азотных удобрений помогает проявить урожайный потенциал культуры [14]. Так, при управлении азотным питанием в режиме реального времени (realtime N management = RTNM), азотные удобрения используются в определенной дозе только когда содержание азота в листьях снижается ниже определенного порога [15].…”