Study On The Cultivation Technology Of High Yield And Good Quality In Direct-sown Rapeseed "Chuanyou36"

In order to establish the cultivation technology of high yield and good quality of direct-sown rapeseed for mechanized production, five field trails (sowing date, nitrogen applied rates, nitrogen applied times, plant density and row place, N rates and plant density) with the same variety (Chuanyou36) were conducted in 2014-2015 under two sites of (Guanghan, Chongzhou) Chengdu Plain. The results showed that:(1) Yield, pods per plant and some agronomic traits (plant height, first branch height, main inflorescence length, number of first branch) of direct-sown rapeseed were obviously or significantly decreased with postponed sowing date. But it was no significant difference of seed yield between D1 treatment and D2 treatment. There was an increase trend of grains per pod with postponed sowing date. There was no significant difference of thousand grain weight, seed oil content and seed protein content between different treatments of sowing date.(2) Compared with NO treatment, yield, pods per plant and some agronomic traits (plant height, main inflorescence length, number of first branch) of direct-sown rapeseed were obviously or significantly increased under the N application treatments. There was no significant difference of seed yield among three N application treatments (N9, N12, N15). Seed oil content decreased with the adding of N applied rates, but seed protein content obviously or significantly increased. There was an obviously or significantly declined trend of N fertilizer agronomic efficiency and partial factor productivity but an increased trend of N fertilizer contribution rate with the increase of N applied rates. But there were no significant differences of N fertilizer agronomic efficiency and contribution rate under different applied N rates (N6,N9,N12,N15).(3)There were no significant differences of seed yield, yield components, seed quality first branch height, pods of main inflorescence and number of first branch in direct-sown rapeseed under different N application methods (times).(4) There were no significant differences of seed yield, seed quality and agronomic traits under different plant density or row place. Plant height and first branch height were decreased but increased for pod per plant with the increase of row place at the same plant density (M2 or M3). Seed yield of L40 treatment was higher than other row place treatments relatively.(5) Seed yield of direct-sown rapeseed was significantly effected by the interaction of N applied rates and plant density. The seed yield of N15 treatment was significantly higher than N9 treatment at the same plant density (Ml or M2). However, there was no significant difference between N15 treatment and N9 treatment at the same plant density (M4).Based on the results of agronomic traits, yield, quality and N fertilizer use efficiency, further combine with the consideration of lodging resistance and mechanized harvesting requirements, the cultivation technology of high yield and good quality of direct-sown rapeseed has been summarized under Chengdu Plain rice-rapeseed rotation system and medium soil fertility. It consists of sowing date (early October), plant density (2?3×104plant/667m2), row place (30cm-40cm), N applied rate (9?12kg/667m2) and N applied method (basal fertilizer + one time topdressing).