Abstract:

To compare the effects of different manures on the physicochemical properties of red soil and maize yield, so as to provide theoretical basis for improving red soil productivity in Yunnan Plateau. A site-specific field experiment was conducted from 2011 to 2019 in Qujing, Yunnan. The experiment was designed for five treatments, namely winter fallow cropland-maize (CK), winter fallow cropland-maize under applying decomposed farmyard manure (FM), planting radish and ploughing in its fresh grass-maize (R), planting vetch and ploughing in its fresh grass-maize (V), winter fallow cropland-maize under maize straw turnover (MS). Each year soil samples from 0-20 cm underground were collected to test its physical and chemical properties after harvesting maize and measure its yield for each treatment. The results showed that compared with CK, R, MS, FM and V increased the organic matter content by 3.92%-14.03%, and increased the content of rapidly available potassium by 6.64%-76.63%, while the bulk density reduced by 6.22%-10.50%. The content of alkali-hydrolyzed nitrogen increased by 0.70%-24.18% for treatments of R, FM and V while it reduced by 0.31% for MS treatment. The content of available phosphorus increased 43.74% for the FM treatment while available phosphorus content reduced by 2.73%-8.20% for treatments of MS, V, R. Maize yield increased 217, 377, 537 kg/hm² for treatments of MS, V and FM, respectively, but reduced 474 kg/hm² for treatment R. The maize yield of FM, V was significantly higher than that of treatment R. Different manures could increase the content of organic matter and rapidly available potassium and reduce the bulk density of red soil. FM and V increased obviously the content of alkali-hydrolyzed nitrogen, and there was no significant change for the treatment of MS and R. FM notably increased content of available phosphorus, but MS, V and R consumed soil available phosphorus at different levels. FM increased the most maize yield and the most content of available phosphorus and rapidly available potassium. V increased the most content of organic matter, alkali-hydrolyzable nitrogen and more maize yield and decreased the most bulk density. R increased the least of organic matter, alkali-hydrolyzable nitrogen and rapidly available potassium and reduced more bulk density, and harvested lower maize yield.

Key words: manure, radish (Raphanus sativus L.), vetch (Vicia villosa Roth. var.), maize straw, red soil, productivity