Peanut production in saline-alkali land of Yellow River Delta: influence of spatiotemporal changes of meteorological conditions and soil properties.

Abstract

Background: This study clarified the synergistic relationship among annual changes to specify the changes in agro-meteorological factors, soil characteristics and peanut growth in saline-alkali land near the estuary of the Yellow River Delta. We aimed to find the key factors affecting peanut production to optimize and regulate peanut planting mode in saline alkali soil.

Results: The daily average temperature from early May to late September in Lijin and Kenli was above 24 °C, with 470-600 mm of precipitation. The sunshine duration was 7.9 h/day and 7.3 h/day and the accumulated temperature was 3742 °C and 3809 °C, in Lijin and Kenli, respectively. Agro-meteorological conditions were suitable for peanut growth and development with the consistent main developmental period in the two experiment regions. The best sowing period was when the soil temperature stabilized above 18 °C in early May, and the best harvest was in mid-September. The soil volumetric water content in Lijin concentrated among 25-40%. Salt was mainly distributed in the 40-60 cm soil layers, and increased rapidly to 2.5 g kg^- 1 in 0-20 cm cultivation layer in mid-May due to lack of precipitation. In Kenli experiment region, the soil volumetric water content ranged from 10 to 35%. Soil salinity was mainly distributed in the 20 cm soil layer, and the changes in salinity was little affected by precipitation. From mid-July to mid-August, the effective accumulated temperature of 5 cm soil layer was above 520 °C in both regions, which could ensure the normal pod development. The slow dynamic growth of kernel, high unfilled pod rate (26.99%) and low shelling rate (66.0%) might be the main reasons for low peanut yield in Lijin.

Conclusion: Soil salinity was the main factor affecting pod development and yield. It was also a key point in optimizing the peanut planting mode in the saline alkali land of the Yellow River Delta.