Exploring 65 years of progress in cotton nutrient uptake, efficiency and partitioning in the USA

Cotton is a vital crop worldwide, and as increases in population and changes in climate occur, it is critical for breeders to continue to improve lint yields. One area to further investigate is how nutrient uptake and nutrient use efficiencies have changed through time to develop future management and breeding strategies. To evaluate the change in nutrient uptake, nutrient use efficiency and yield of 20 cotton cultivars released in the USA between 1953 and 2018. A field experiment in 2020 and 2021 was carried out to evaluate the nutrient uptake, internal nutrient use efficiency and partitioning of assimilated nutrients among different components of biomass for the twenty cotton cultivars released between 1953 and 2018 in the USA. Linear regression analysis was performed to estimate the rate of gain for lint yield, crop biomass, total nutrient uptake and use efficiency. The rate of genetic gain for crop biomass increased 4.3 times faster than the rate of gain for lint yield. The total nutrient uptake and internal use efficiency were significantly different among cultivars, with a consistent increase measured across the span of years of release for the 20 cultivars. Nutrient concentration in vegetative growth either decreased or remained unchanged over time, while concentration in the seed increased. Modern cultivars demonstrate a 27% increase in efficiency, producing more lint per unit of nutrient uptake compared to those from the 1950 s, owing to improved nutrient availability with limited seed partitioning. Partitioning of total assimilated nutrients of N, P and K into the different biomass components were inconsistent over the years. Modern cotton cultivars have shown an increased total nutrient uptake but a slower improvement in nutrient use efficiency. The limited changes observed in the partitioning of primary nutrients for reproductive growth, along with the increased concentration of nutrients in seed, suggest potential focus for future advancements in breeding strategies. This research offers valuable perspectives on nutrient uptake, partitioning and use efficiency of cotton cultivars released between 1953 and 2018. Differences in nutrient use efficiency among cultivars were observed, highlighting the potential for enhanced nutrient uptake traits in cotton. These findings indicate that improved nutrient partitioning along with associated fertility recommendations could strategically direct future cultivar development.