Climate suitability determines optimal yielding of dryland maize: A validation on timely sowing as an ancient wisdom

Abstract

Context

Climate-based timely sowing is an ancient wisdom, which can facilitate crops to sufficiently utilize climate resources and harvest optimal yielding. However, few studies have validated or addressed this issue from the perspective of climate suitability degree in association with crop maturity and sowing dates.

Objective

1) To explore the sole and integrated effects of sowing dates and crop maturing on maize growth and yielding in dry and wet growing seasons; 2) To reveal the mechanisms of appropriate sowing date affecting yield formation in association of climatic resource utilization; and 3) to validate the ancient wisdom of timely sowing in agricultural production.

Methods

A two-year field experiment was conducted to evaluate the effects of three sowing dates (advanced, SD1; timely, SD2; delayed, SD3) and three maize varieties with early-, medium- and late- maturing (EM, MM and LM) in northwest China. Dry matter accumulation, grain yield, climatic suitability degree, and other related parameters were determined and analyzed.

Results and conclusion

Maize yield performance varied from the growing seasons (dry 2017 and wet 2018) under different sowing dates, but followed a similar trend between two years (i.e. two growing seasons, the same below). In 2017, maize yield was 11.3 % and 22.4 % greater in SD2 than that of SD1 and SD3, respectively (p < 0.05). Similarly, in 2018, it increased by 11.1 % and 18.3 % in SD2 respectively, relative to SD1 and SD3 (p < 0.05). As for the medium- and late-maturing varieties, it appeared to be 7.3 % and 9.8 % greater in 2017, and 25.2 % and 28.6 % greater in 2018 respectively, than the early-maturing one (p < 0.05). Overall, the optimal yielding performance was observed in the late-maturing variety under SD2, up to 7.2 ton ha⁻¹ in 2017 and 10.38 ton ha⁻¹ in 2018 respectively, followed by the medium-maturing variety under SD2. Mechanistically, the highest climate suitability degree across whole growth period (S(C)wgp) was observed in SD2 across three varieties. Regardless of crop maturity, the S(C)wgp was significantly positively correlated with main agronomic traits. Particularly, crop growth rate, leaf area duration, net assimilation rate and maximum relative dry matter accumulation rate performed significantly better in SD2 than those of SD1 and SD3, suggesting that appropriate sowing time can maximize yield potential.

Implications or significance

The findings underscore the importance of timely sowing in maize production, confirming the reasonability and feasibility of timely sowing as an ancient agricultural wisdom based on climate suitability degree.