Long-term maize straw substituted for chemical fertilizers promoted rice
yield due to the altered soil properties in the red paddy soil
Abstract
Despite straw application within rice agriculture being widely
practiced, both in China and globally, there remain few studies on the
maize straw substituted for chemical fertilizers. In this study, maize
straw substituted for chemical fertilizers to a double-cropping rice
field and compared the effects of medium (MS 9,600 kg·ha−1·year−1) and
high (HS 19,200 kg·ha−1·year−1) application on rice yield and soil
characteristics with that of the application of single chemical
fertilizers (CF) over a period of 1982 to present. The yields of late
and early rice increased by 42.66 and 25.04% in 2019 and 2020,
respectively. The soil bulk density of MS and HS decreased significantly
by 15.94 and 33.35% compared with that of CF, whereas total soil
porosity increased significantly by 9.46 and 20.17%, respectively.
Long-term straw application significantly improved the soil stable
aggregates content (> 0.25 mm). Straw application increased
soil urease, protease, alkaline phosphatase (ALP), acid phosphatase
(ACP) and catalase activities, microbial biomass carbon (C), microbial
biomass nitrogen (N), and soil nutrients content compared with CF,
especially HS. Correlation analysis showed that double-cropping rice
yield was highly significantly correlated with soil bulk density, total
porosity, catalase, microbial biomass C, microbial biomass N, and
available P. In conclusion, maize straw substituted for chemical
fertilizers not only makes rational use of straw resources, but also
improves soil characteristics to improve crop yield.