Effect of introducing frogs and fish on soil phosphorus availability dynamics and their relationship with rice yield in paddy fields

Abstract

The long-term impacts of introducing frogs and fish on rice yield and soil P availability are largely underestimated and undervalued. A 9-year field experiment compared the soil phosphorus fraction dynamics and their relationship with rice yield in rice-frog-fish (RFF) cultures, rice-fish (RF) cultures and rice-only (RO) cultures in southeastern China paddy fields. The yields in the RFF and RF cultures were notably higher than those in the RO culture, by 22.1% and 6.8%, respectively. Soil total P ranged from 345.5 to 385.6 mg kg −1 among all the farming systems, with the smallest amount found in the RO culture. There were only slight changes in the distribution of soil phosphorus fractions with time. The concentrations of NaHCO 3-Pi and NaHCO 3-Po were significantly higher in the RFF and RF cultures compared with those in the RO culture, and most of the NaOH-Pi and NaOH-Po fractions were greater in the RFF and RF cultures compared with those in the RO culture. The rice grain yield was significantly correlated with labile P and slowly cycling P. Introducing frogs and fish might be useful for increasing soil active P supplies and meeting rice nutrient requirements. This study concluded that RFF is the best practice for improving rice grain yields and soil fertility in paddy fields.

Effects of introducing eels on the yields and availability of fertilizer nitrogen in an integrated rice–crayfish system

“…Moreover, the rice yields may be enhanced by multispecies complex rearing in the rice field. This viewpoint was also demonstrated by other scholars 24,25 . Lin and Wu found that the rice yields were significantly higher in the rice-frog-fish system than in rice-fish co-culture and rice monoculture 25 .…”

“…This viewpoint was also demonstrated by other scholars 24,25 . Lin and Wu found that the rice yields were significantly higher in the rice-frog-fish system than in rice-fish co-culture and rice monoculture 25 . In the rice fields, the eels prefer high temperatures and are usually active in the rice-growing platform.…”

Bacterial communities in paddy soil and ditch sediment under rice-crab co-culture system

“…The rice-fish co-culture system composes of two parts: paddy and ditch. As the main part of the system, paddy has been subjected to multiple studies on soil nutrients status, bacterial community structure, and greenhouse gas (Bashir et al 2021 ; Lin et al 2020 ; Li et al 2019 ). The ditch is similar to traditional pond culture and plays an important role in the growth of aquaculture animal.…”

Analysis of ‘RICE’ benefits on rice–tortoise ( Chincmys reevesii ) co‐culture system

“…(2) I-benefit, it meant that the system could increase food supply, product quality and farmer incomes (Hu et al, 2016;Li et al, 2020;Zhang et al, 2016). For instance, the grain yields in the farming systems of rice-frog-fish (RFF) and the rice-fish (RF) were notably higher 22.1% and 6.8% than that in the rice-only (RO) system respectively (Lin & Wu, 2020). (3) C-benefit, there was a mutually beneficial relationship between rice and fish in co-existence system, in which the activities of fish were beneficial to the growth of rice, and rice also could benefit for fish by being able to provide shade and lower water temperature during the hot season (Hu et al, 2016;Xie et al, 2011;Zhang et al, 2016).…”

“…Many studies focused on the development advantages of co-culture systems which have been reported in fish, especially in China, with a long history of more than 1200 years (Halwart & Gupta, 2004;Lin & Wu, 2020). What's more, in recent years, the system had aroused great enthusiasm among the farmers and gained a lot of support from the government due to positive benefits, and there were many different cultivation patterns and techniques for rice-fish, rice-crab, rice-duck and rice-prawn-fish by local farmers (Hu et al, 2016;Teng et al, 2016;Wahab et al, 2008).…”