Effects of Reducing Nitrogen and Increasing Density on Yield and Cadmium Accumulation and Transportation of Chuangliangyou 669 in Hybrid Rice
In order to investigate the effects of reducing nitrogen and increasing density on yield and cadmium accumulation and transportation of hybrid rice,using Chuangliangyou 669 as the materials,three nitrogen levels(N1180 kg/hm2,N2 153 kg/hm2,N3 126 kg/hm2)and two densities(M1 20.0 cm×16.7 cm,M2 16.7 cm× 16.7 cm)were applied in a field experiment with the paddy fields polluted by cadmium in Chenzhou,Hunan Province.The results showed that nitrogen reduction reduced the dry matter weight,the number of effective panicles,the number of spikelets per panicle and yield of rice.However,increasing density improved the number of effective panicles and yield.Under the experimental conditions,N1M2 treatment had the highest yield,followed by N2M2 treatment.The effects of density increase on cadmium uptake and transport in rice was different among years and organs,but nitrogen reduction reduced the available cadmium content in soil and the cadmium transport coefficient from root to leaf,thereby reducing the cadmium content in some organs.The cadmium content in brown rice under N1 treatment was higher than the national standard(0.20 mg/kg),while the cadmium content in brown rice of N2 and N3 treatments,significantly lower than that of N1 treatment,was lower than the national standard.In a word,the reduction of cadmium content in rice was mainly realized by reducing nitrogen application,and a 15％to 30％reduction in nitrogen can bring the cadmium content in brown rice below the national safety standard.Considering both yield and cadmium content of brown rice,N2M2(15％nitrogen reduction & densification)is the optimal treatment for achieving a significant reduction in cadmium content of brown rice while achieving a higher yield.
hybrid ricereducing nitrogen and increasing densityyieldcadmium accumulation and transportationsoil available cadmium
万方数据
维普
