Water mimosa (Neptunia oleracea Lour.) can fix and transfer nitrogen to rice in their intercropping system

Abstract

BACKGROUND: Cereal-legume intercropping systems are an environmentally friendly practice in sustainable agriculture. However, research on the interspecific interaction of nitrogen (N) between rice and aquatic legumes has rarely been undertaken. To address this issue, a pot experiment was conducted to investigate N utilization and the N interaction between rice and water mimosa (Neptunia oleracea Lour.) in an intercropping system. The root barrier patterns consisted of solid barrier (SB), mesh barrier (MB), and no barrier (NB) treatments. The N fertilizer application rates were low, medium, and high N rates. RESULTS:The results showed that the NB treatment better facilitated rice growth compared with the MB and SB treatments. And the nitrate N content and urease activity of rice rhizospheric soil in the NB treatment were the highest of the three separated patterns. The ammonium N content in water mimosa rhizospheric soil and N 2 fixation of water mimosa ranked as NB > MB > SB.CONCLUSIONS: The amount of N fixation by water mimosa was 4.38-13.64 mg/pot, and the N transfer from water mimosa to rice was 3.97-9.54 mg/pot. This can promote the growth of rice and reduce the application of N fertilizer. We suggest that the rice-water mimosa intercropping system is a sustainable ecological farming approach and can be applied in the field to facilitate rice production.

Mix‐cropping of rice and water mimosa (Neptunia oleracea Lour.) increases rice photosynthetic efficiency, yield, grain quality and soil available nutrients

“…Previous studies also found that intercropping resulted in reduced growth attributes owing to inter‐species and intra‐species competition for growth resources compared with monoculture 34‐36 . However, in rice/water mimosa inter‐cropping or mix‐cropping system, rice was a stronger competitor and water mimosa was a weaker competitor 25 . Thus, rice growth better in these two cropping systems in our study.…”

“…[34][35][36] However, in rice/water mimosa inter-cropping or mix-cropping system, rice was a stronger competitor and water mimosa was a weaker competitor. 25 Thus, rice growth better in these two cropping systems in our study.…”

“…The higher N uptake of rice could be attributed to the fact that water mimosa fixed N from the atmosphere and transfered it to rice. 23,25 As a consequence, intercropping and mix-cropping systems were both conducive to the dry weight and nutrient uptake of rice.…”

“…[21][22][23][24] A previous study found that the intercropping of rice with water mimosa increased soil N fertility and rice productivity. [23][24][25] However, there has been no research to evaluate the rice yield and soil nutrients in the rice/water mimosa mix-cropping system.…”

“…), a leguminous vegetable, can fix N from the atmosphere and is consumed in some Asian countries because of its high nutritional value 21‐24 . A previous study found that the intercropping of rice with water mimosa increased soil N fertility and rice productivity 23‐25 . However, there has been no research to evaluate the rice yield and soil nutrients in the rice/water mimosa mix‐cropping system.…”