Effects of wheat straw incorporation and nitrogen application on sweetpotato yield and quality and soil fertility

ABSTRACT

The study was aimed to determine the effect of wheat straw incorporation and nitrogen (N) fertilization on soil fertility and enzyme activity, as well as sweetpoato yield and quality. Field experiment was conducted in the summer seasons of 2017 and 2018, and four treatments were set: zero straw +50 kg·ha⁻¹N (S₀N₅₀), 50% straw return +50 kg ha⁻¹N (S₁N₅₀), 100% straw return +50 kg·ha⁻¹N (S₂N₅₀), 100% straw return+150 kg ha⁻¹N (S₂N₁₅₀). The aboveground yield, storage roots yield and single root fresh weight increased with the increase of straw returning quantity(S₂N₅₀> S₁N₅₀> S₀N₅₀). The storage root yield ofS₂N₁₅₀in 2017 was higher than that ofS₂N₅₀,but lower than that ofS₂N₅₀in 2018. Two years of nitrogen/straw incorporation also increased the starch content of sweetpotato, but decreased the reducing sugar, soluble sugar and protein content. The available N, total N, available P, available K and organic matter content, as well as catalase, alkaline phosphorylase, urease and invertase activity in soil were enhanced by nitrogen/straw incorporation. The results indicated that the conjoint application of full amount of straw and appropriate amount of N had the best effect on increasing the yield and starch content of sweetpotato.

KEYWORDS:

• Sweetpotato
• straw management
• soil properties
• nutritional quality

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Ministry of Agriculture of the People’s Republic of China with funds earmarked for the China Agriculture Research System (CARS-10-B11), the National Natural Science Foundation of China (31771721, 31461143017-2), and the National Key R&D Program of China[2018YFD1000704-10]