Equal K Amounts to N Achieved Optimal Biomass and Better Fiber Quality of Late Sown Cotton in Yangtze River Valley

Xiaolei Ma,Anda Liu,Adnan Noor Shah,Abdul Hafeez,Zhao Zhang,Saif Ali,Dan Luo,Guozheng Yang,Jiahao Liu

doi:10.3390/agronomy10010112

Xiaolei Ma, Anda Liu + Show 7 more

Open Access

https://doi.org/10.3390/agronomy10010112

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Abstract

Potassium (K) fertilizer plays a crucial role in the formation of the biological and economic yield of cotton (Gossypium hirsutum L.). Here we investigated the effects of the amount of K on biomass accumulation and cotton fiber quality with lowered N amounts (210 kg ha−1) under late sowing, high density and fertilization once at 2 weeks after squaring. A 2-year field experiment was performed with three K fertilizer amounts (168 kg ha−1 (K1), 210 kg ha−1 (K2), and 252 kg ha−1 (K3)) using a randomized complete block design in 2016 and 2017. The results showed correspondingly, K3 accumulated cotton plant biomass of 7913.0 kg ha−1, next to K2 (7384.9 kg ha−1) but followed by K1 (6985.1 kg ha−1) averaged across two growing seasons. Higher K amounts (K2, K3) increased biomass primarily due to a higher accumulation rate (32.68%–74.02% higher than K1) during the fast accumulation period (FAP). Cotton fiber length, micronaire, and fiber strength in K2 were as well as K3 and significantly better than K1. These results suggest that K fertilizer of 210 kg ha−1 should be optimal to obtain a promising benefit both in cotton biomass and fiber quality and profit for the new cotton planting model in the Yangtze River Valley, China and similar climate regions.

Highlights

Cotton is one of the most important fiber crops grown for fiber and for the paper and oil industries [1,2]
Valley is one of the three cotton-growing regions in China where seedlings are transplanted after wheat or rapeseed is harvested and more than 300 kg ha−1 N is applied in three splits (30% at pre-plant, 40% at first bloom, and 30% at peak bloom) [3,4]
Cotton flowering and boll setting period took the longest while squaring the shortest, differences existed between years in each specific cotton growth period (Table 1)

Summary

Introduction

Cotton is one of the most important fiber crops grown for fiber and for the paper and oil industries [1,2]. A new planting model with late sowing (mid-May) [6], high density (9–10 plants m−2 ) [6,7], low N amounts (180–225 kg ha−1 ) [7], and once fertilization [3,8] has been practiced as an effective way to fight the challenge of high cost in cotton production in the region. The new planting model harvested similar yield to the conventional practice [9] but greatly reduced the cost resulted from less manual work, low N fertilizer amount and less application of chemicals, due to the short cotton growing season with high planting density

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Discussion

Conclusion