Investigation On Fertilization And Effect Of Formulated Fertilization Of Winter Rapeseed In Yangtze River Basin

The planting and fertilization of winter rapeseed in11provinces inYangtze River Basin including Hubei, Hunan, Anhui, Jiangxi, Henan, Sichuan, Yunnan, Chongqing, Guizhou, Jiangsu and Zhejiang were studied by sampling investigation. Effects of formulated fertilization were researched through1240demonstration trials. Some factors were analyzed such as planting patterns, varieties and amounts of chemical fertilizer and manure, times of fertilization, ratio of base and toptressing and economic benefits. The condition of planting and farmers’fertilization on winter rapeseed was clarified in Yangtze River Basin. The existing problems were pointed out. Combined with data of demonstration trials (no fertilization, farmers’fertilization and formulated fertilization) of winter rapeseed, the differences were compared in the yield, fertilizer rate, fertilizer use efficiency and economic benefits between farmers’and formulated fertilization. The main results are listed as follows.1Planting and fertilization of rapeseed and the temporal and spatial variation was elucidated by3197questionnaires.1.1Planting patterns:Transplanting was the main pattern in the lower reaches of the Yangtze River, while direct-seeding and transplanting rapeseed presented the similar proportion in the upper, middle and whole reaches of the Yangtze River. Transplanting was the primary planting pattern in Chongqing, Yunnan and Henan Province, while the pattern in Sichuan, Guizhou, Anhui, Jiangsu and Zhejiang Province was direct-seeding. The two patterns had the similar proportion in Hubei and Hunan Province.1.2Fertilizer variety:More than99%of farmers applied chemical fertilizer such as urea, compound fertilizer, ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer. The most popular varieties of fertilizer for application were the urea and compound fertilizer, while potassium chloride and boron fertilizer were applied at low proportion. Approximately50%of farmers applied manure, and the application proportion decreased from upper to lower reaches. The varieties of manure contained human excreta, animal manure (pig, cattle, sheep and chicken faces), plant ash, rapeseed cake, soil manure. The common varieties were human excreta and plant ash.1.3Fertilizer input: The average input of chemical N, P2O5and K2O fertilizer was175,54and42kg/hm2, respectively and the ratio was1:0.35:0.27in2010/2011. The input of N, P2O5and K2O from chemical resources accounted for91.6%,81.8%and60.0%, respectively. In general, N fertilizer was used sufficiently while K fertilizer insufficient. According to classification, the proportion of farmers applying chemical N fertilizer less than150kg/km2and more than270kg/hm2was47.4%and15.8%, respectively, which indicated that there existed insufficient and excessive application of N fertilizer simultaneously. The proportion of farmers applying chemical P fertilizer less than45kg/km2and higher than75kg/hm2was50.9%and23.5%, respectively. It was showing that about half of farmers used P fertilizer insufficiently. The proportion of farmers using chemical K fertilizer less than75kg/hm2and more than105kg/hm2was83.7%and7.8%, respectively, denoting that about80%of farmers applied K fertilizer insufficiently. The application amounts of chemical N fertilizer exhibited large differences in the Yangtze River Reaches. For example, the application amount in the Lower Reaches was higher than that in the Upper and Middle Reaches. The application amount was relatively high in Jiangsu and Sichuan Province. However, the amount was comparatively low in Jiangxi and Chongqing Province.1.4Fertilization technique:The average fertilization frequency for rapeseed was2or3times including1or2times top-dressing during whole growth season in the Yangtze River Basin. The direct-seeding rapeseed showed lower times of fertilization application as compared to transplanting rapeseed. The fertilization times followed the sequence of Upper Reaches<Middle Reaches<Lower Reaches. Lower application frequency was found in Sichuan, Chongqing and Jiangxi Province than Jiangsu, Zhejiang and Anhui Province. The common model of farmer fertilization was applying fertilizer at seedbed or seeding stage followed by basal fertilizer and top-dressing fertilizer in Upper and Lower Reaches. Basal and1time top-dressing fertilizer was presented in Middle Reaches. The proportion of basal N fertilizer was between30%and70%and the average was50%. P and K fertilizer were usually used as basal fertilizer.1.5Economic benefits:The average unit yield was1923kg/hm2in the Yangtze River Basin in2010/2011. On average, the material cost was2283yuan/hm2. The net income was6437yuan/hm2. The ratio of output to input was3.8. The net income in Jiangsu and Zhejiang Province was relatively high and that in Chongqing, Hunan and Jiangxi Province was comparatively low.1.6Temporal changes:Compared with the results of2007/2008, the proportion of direct-seeding rapeseed increased in2010/2011. And the application amount and basal fertilization of N fertilizer decreased as well as the the proportion of excessive application of N fertilizer. As a result, the material input and net income decreased.2The difference in farmers’and formulated fertilization was compared though1240demonstation trails.2.1Yield effect:In contrast to no fertilization, more than99%of formulated fertilization and accustomed fertilization trials increased yield. The increment of yield of formulated and accustomed fertilization was1246kg/hm2and928kg/hm2, respectively and the increment rate was122.7%and91.8%, respectively. The fertilization on rapeseed showed significant yield-increasing effect. Compared with accustomed fertilization, the average yield increment of formulated fertilization was311kg/hm2and the increment rate was14.9%on average. The results suggested that the yield-increasing effect from formulated fertilization was better than accustomed fertilization. 2.2Application amount of fertilizer: The average application amount of N fertilizer of formulated and accustomed fertilization was174kg/hm2and175kg/hm2, while that of P fertilizer was76kg/hm2and66kg/hm2, and that of K fertilizer was90kg/hm2and50kg/hm2, respectively. The application amounts of N, P and K fertilizer were compared between formulated and accustomed fertilization on trials which the increment rate of yield was higher than5%. There were51.0%of formulated fertilization trials increasing application amount of N fertilizer, while41.7%of trials decreasing the amount. There were60.5%and83.2%of formulated fertilization trials increasing the application amount of P2O5and K2O fertilizer. The results indicated that the significant yield-increasing effect was achieved in formulated fertilization through rational regulation of application amount of N fertilizer including decreasing and increasing N fertilizer, and increasing the application amount of P and K fertilizer.2.3Fertilizer use efficiency:The fertilizer use efficiency of N fertilizer was34.8%for formulated fertilization and27.4%for accustomed fertilization. The fertilizer use efficiency for P fertilizer of formulated and accustomed fertilization was25.2%and20.3%, and for K fertilizer was42.1%and38.1%, respectively. The results showed that the fertilizer use efficiency of formulated fertilization was higher than that of accustomed fertilization.2.4Economic benefits:In contrast to accustomed fertilization, formulated fertilization increased324yuan/hm2in the input of fertilizer. The net income increased1178yuan/hm2when deducted the fertilizer cost. It was evident that the formulated fertilization resulted in better income increases than accustomed fertilization.In a word, the current problems of farmer accustomed fertilization on winter rapeseed in the Yangtze River Basin are as follows. The application proportion of K and B fertilizer was relatively low. The application amount of N fertilizer was sufficient, whereas there exist excessive and insufficient application simultaneously. P and K fertilizer was still lacking in the application amount and the ratio of N:P2O5:K2O was inconsistent. Top-dressing fertilizer was usually applied one time, and the proportion of basal fertilizer was unreasonable in part areas. The fertilizer use efficiency of formulated fertilization was increased by the rational regulation of N fertilizer amount and the application amount of P and K fertilizer under the same application amount of N fertilizer to accustomed fertilization. The increases in yield and income by formulated fertilization were higher than those of accustomed fertilization.