The evidence pointed to a method for reducing the environmental disadvantages connected with rice cultivation, as well as possible economic gains for rice producers.
Modern farms sometimes cultivate only one type of crop, necessitating vast quantities of fertiliser and pesticides. This has aided agricultural productivity but at the expense of more environmental damage. Some farmers are experimenting with producing a combination of crops and animals in order to lessen the need for agricultural chemicals by taking advantage of favourable plant-animal interactions.
“One example is farmers experimenting with rearing aquatic creatures in rice paddies,” explains co-first author Liang Guo, Postdoctoral Fellow at Zhejiang University’s College of Life Sciences in Hangzhou, China. “Learning more about how these creatures contribute to rice paddy ecosystems might assist with more sustainable rice production.”
Guo and colleagues conducted three four-year tests to compare rice growth with carp, mitten crabs, or softshell turtles to rice growth alone. They discovered that aquatic animals decreased weeds, enhanced organic waste decomposition, and boosted rice yields when compared to rice farmed alone.
“We also found that nitrogen levels in the soil remained stable in rice fields containing aquatic animals, lowering the requirement for nitrogen-based fertilisers,” explains co-first author Lufeng Zhao, a PhD student at Zhejiang University’s College of Life Sciences.
The researchers next looked at what the animals ate in the rice paddies. They discovered that plants and other things they scavenged made up 16-50 per cent of their diet, rather than their feed. They also discovered that rice plants utilised around 13-35 per cent of the nitrogen from residual feed that was not consumed by the animals.
Growing rice with aquatic creatures resulted in yields that were 8.7 to 12.1 per cent greater than yields from rice cultivated alone. Farmers were also able to raise between 0.5 and 2.5 tonnes of crabs, carp, or turtles per acre in addition to rice.
“These findings improve our understanding of the roles of animals in agricultural ecosystems and support the view that growing crops alongside animals have a number of advantages,” says Xin Chen, Professor of Ecology at Zhejiang University’s College of Life Sciences and co-senior author of the study with Dr Liangliang Hu and Professor Jianjun Tang. “Adding aquatic creatures to rice paddies may enhance farmers’ profitability since they can sell both the animals and the rice, spend less on fertiliser and pesticides, and charge more for sustainably cultivated items.”
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