[Effects of organic fertilizer application on accumulation and distribution of assimilates in winter wheat].

To understand the effects of organic fertilizer addition on accumulation and distribution of winter wheat assimilates, we compared organic carbon content in soil and wheat plants, photosynthetic characteristics and assimilation transformation under two different fertilizer treatments, CF (chemical fertilizer only) and OF (organic fertilizer with chemical fertilizer), using ¹³ CO ₂ pulse labeling method. The results showed that OF increased soil organic carbon content and wheat photosynthetic parameters, resulting in higher organic carbon content and total dry biomass accumulation in wheat plants compared with CF treatment. Compared marking to maturity with that on the 7th day after the same marking, the content and distribution rate of ¹³ C in leaves and stems of two treatments decreased; the ¹³ C content in spikes increased at jointing stage and filling stage, decreased at anthesis stage, and the ¹³ C distribution rate increased at all stages. OF treatment was more beneficial for the transportation of photosynthetic product from leaves to spikes at filling stage, with higher ¹³ C distribution rate in spikes compared with CF treatment. The results of correlation analysis showed that dry matter accumulation was significantly positively correlated with the net input of ¹³ C content and its distribution rate, but negatively correlated with organic carbon content in plants. The net input of ¹³ C content was significantly positively correlated with its distribution rate, and negatively correlated with F _v /F _m and P _n . In conclusion, organic fertilizer application could increase the content of organic carbon in soil, improve wheat plants photosynthetic capacity and transportation of photosynthetic product to spikes, and ultimately increase dry matter accumulation in wheat spikes.