Establishment of an NPK nutrient monitor system in yield-graded cotton petioles under drip irrigation.

Background: The determination of nutrient content in the petiole is one of the important methods for achieving cotton fertilization management. The establishment of a monitoring system for the nutrient content of cotton petioles during important growth periods under drip irrigation is of great significance for achieving precise fertilization and environmental protection.

Methods: A total of 100 cotton fields with an annual yield of 4500-7500 kg/ha were selected among the main cotton-growing areas of Northern Xinjiang.

Effect of different NPK fertilization timing sequences management on soil-petiole system nutrient uptake and fertilizer utilization efficiency of drip irrigation cotton.

In order to elucidate the effects of different nitrogen (N), phosphorus (P), and potassium (K) fertilization timing sequences management on nutrient absorption and utilization in drip irrigation cotton, field experiments were conducted from 2020 to 2021. There are six timing sequences management methods for NPK fertilization (S1-S6: 1/3Time N-1/3Time PK-1/3Time W, 1/3Time PK-1/3Time N-1/3Time W, 1/2Time NPK-1/2Time W, 1/4Time W-1/4Time N-1/4Time PK-1/4Time W, 1/3Time W-1/3Time NPK-1/3Time W), among which S6 is the current management method for field fertilization timing sequences, and S7 is the non N. The results showed that during the main growth stage, S5 accumulated more nitrate nitrogen (NO-N) and ammonium nitrogen (NH-N) content in soil between 20 and 40 cm, and accumulated more available phosphorus content in soil between 5-15 cm and 15-25 cm, S5 reducing N leaching and increasing P mobility.

Estimation of nitrate nitrogen content in cotton petioles under drip irrigation based on wavelet neural network approach using spectral indices.

Background: Estimation of nitrate nitrogen (NO-N) content in petioles is one of the key approaches for monitoring nitrogen (N) nutrition in crops. Rapid, non-destructive, and accurate evaluation of NO-N contents in cotton petioles under drip irrigation is of great significance.

Methods: In this study, we discussed the use of hyperspectral data to estimate NO-N contents in cotton petioles under drip irrigation at different N treatments and growth stages.