Potentials of straw return and potassium supply on maize (Zea mays L.) photosynthesis, dry matter accumulation and yield

Abstract

Maize (Zea mays L.) is considered one of the most important grains in the world. Straw return and potassium fertilization can enhance the maize yield. Therefore, three field experiments were carried out in the three years (2018–2020) to study the effects of straw return at two methods and four levels of potassium fertilization on photosynthesis, dry matter accumulation and yield of the maize ‘Xianyu 335’. To conduct the field trials, a split plot system in five replications was established. Two straw return methods (straw return with deep tillage and straw mulching with no tillage) were in the main plots, and four potassium fertilization levels (0, 30, 45 and 60 kg/ha) were in the subplots. Each sub-plot consisted of 10 rows with 5 m length and 0.6 m width, and each sub-plot area was 30 m2 in the three years. The results indicated that the straw return methods and the potassium supply significantly affected the maize photosynthesis, dry matter accumulation and yield in the three years. Under the same potassium supply, straw return with deep tillage significantly improved the maize photosynthesis, dry matter accumulation and yield compared to straw mulching with no tillage. The above characteristics improved with increased potassium supply. The treatment of SFK60 recorded the highest values for the parameters of maize photosynthesis, dry matter accumulation and yield during the three harvest seasons. The treatment of SFK45 reached maximum profit of maize planting, which was 12088.77 yuan/ha. Therefore, SFK45 was an effective way to ensure the stable and higher yields of maize and to maximize the income of farmers.