The Estimation of Nitrogen Uptake and Utilization Efficiency in Cotton by the Fertilizer-Response Model
Due to the indeterminate growth habit of cotton crops, a better understanding of N status at the rational fertilizer regime is important to promote lint yield. The fertilizer-response model was employed to evaluate N status by analyzing data of shoot dry mass, N content and N concentration at different growing stages. A field study was conducted on drip-irrigated cotton plants with N fertilizer addition in total amounts of 0 (N0), 120 (N1), 240 (N2), 360 (N3) and 480 (N4) kg ha-1 in Xinjiang, China in 2016. Thirty percent of total fertilizers were applied at planting and the rest 70% were applied over six applications. The N fertilizer treatment at the accumulative rate of 70 kg ha-1 was enough to induce the N status of steady state accumulation 60 days after germination. Since 90 days the treatments that delivered the N amount between 120 and 240 kg ha-1 was deficient for cotton demand, higher rates from 360 and 480 kg ha-1 induced inherent N reserve and resulted in the highest level of yield. With regard to the practical meaning, the N fertilizer dose of 360 kg ha-1 can be used for cotton growth. The N fertilizer dose of 120 kg ha-1 can be recommended when the yield of 5,840 kg ha-1 lint can meet the goal of cotton culture. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********