Seasonal differences in yield and fertilizer use efficiency of different low-calcium-tolerant peanut varieties in response to the timing and splitting of calcium application in southern China.

Soil Ca deficiency hinders the development of the peanut industry, and inappropriate Ca fertilizer application increases the risk of soil environmental degradation and reduces the fertilizer utilization rate and yield in peanuts. N fertilizer doses are frequently split and applied over different time periods. However, whether this widespread method is applicable to Ca fertilizer and improves peanut growth and yield in southern China requires further investigation. Thus, this study evaluated the effects of timing and splitting Ca applications on the dry matter accumulation and partition, fertilizer use efficiency, and yield of different low-Ca-tolerant peanut varieties (low-Ca-sensitive Jihua 16 and low-Ca-tolerant Yueyou 45) in the early and late seasons. The results showed that the early timing and splitting of Ca application significantly increased the pod yield of Jihua 16 by increasing nitrogen and calcium use efficiencies, dry matter accumulation, and assimilate transfer from vegetative parts to the pods in both years. The highest pod yield of Jihua 16 was obtained with 300 kg CaO ha−1 basal application before sowing and 300 kg CaO ha−1 top-dressing application at the flowering stage (B300:T300) in the early season and 600 kg CaO ha−1 basal application before sowing and 600 kg CaO ha−1 top-dressing application at the flowering stage (B600:T600) in the late season; the yields were significantly increased by 91.87 % in 2020, 92.15 % in 2021, and by 255.36 % in 2020, 248.22 % in 2021, respectively, compared with those obtained with no Ca fertilizer use. However, the Ca treatments did not significantly affect pod yield or the related parameters of Yueyou 45 in either season. The pod yield of both cultivars was higher in the early season than that in the late season because of the higher effective accumulated temperature and precipitation during the reproductive stage in the early season of both years. The results of this study indicate that the early season is most suitable for peanut production, and the B300:T300 and no Ca application strategies are appropriate for the Ca-sensitive and -tolerant cultivars, respectively, in the early season in southern China. Notably, additional Ca-tolerant cultivars should be selected for cultivation in southern China to reduce future fertilizer application. These results provide useful information for improving double-cropping systems, Ca fertilization strategies, and peanut cultivar breeding in southern China. • Higher effective accumulated temperature and precipitation achieved higher yield. • Timing and splitting of calcium application increased the pod yield. • Peanut variety specificity response to the calcium application existed. [ABSTRACT FROM AUTHOR]