早熟与常规熟期冬油菜品种养分吸收规律差异研究

探明南方三熟区早熟与常规熟期冬油菜品种在干物质积累及养分吸收方面的规律差异,为稻-稻-油三熟制油菜施肥提供依据。于2017年冬季至2018年春季在湖南衡阳布置田间小区试验,供试品种为早熟品种湘油420和湘油642、常规熟期品种湘油1035和湘杂油710×1035,间隔10~15d取样,监测4个油菜品种的干物质积累动态,氮、磷、钾元素吸收的时空特征及产量。早熟冬油菜品种与常规熟期冬油菜品种的产量及产量收获指数无显著差异,早熟冬油菜品种的干物质、磷在花期-角果期积累比例最大,分别为79.9%~80.0%、69.3%~79.5%,氮、钾积累量在花期的比例最大,分别为46.8%~47.7%、39.9%~52.3%;常规熟期冬油菜品种的干物质、磷、钾在花期积累比例最大,分别为37.1%~38.6%、44.1%~49.3%、32.8%~36.2%,氮在苗期的积累比例最大（48.6%~73.9%）。相较于常规熟期冬油菜品种,早熟冬油菜品种对干物质及养分的吸收高峰推迟,干物质和磷、钾养分累积多集中在花期-角果期。冬油菜的养分积累量随干物质积累量的增大而提高。早熟冬油菜品种生育期185d,较常规熟期冬油菜品种短15d,能缓解稻油轮作时茬口矛盾;收获期早熟冬油菜品种氮、磷积累量明显高于常规熟期冬油菜品种,氮、磷、钾累积特性适用于缓控释肥养分释放速率慢、周期长的释肥特性。早熟冬油菜品种生育期短且养分积累量高,在南方三熟区存在季节优势和养分积累优势,适宜在南方三熟区大面积推广。

Study on the Difference of Nutrient Absorption between Winter Rape Cultivars at Early Maturity and Conventional Maturity

Difference of dry matter accumulation and nutrient absorption between early maturing cultivars (Xiangyou 420 and Xiangyou 642) and conventional mature cultivars (Xiangyou 1035, hybrid rape Xiangzayou 710×1035) of rape in the triple cropping area of South China, and to provide a basis for fertilization under rice-rice-rapeseed cropping system was explored in this study. A field experiment was conducted in Hunan Hengyang in winter 2017 to spring 2018 years. There was no significant difference in yield and yield harvest index between early maturing winter rapeseed cultivars and conventional mature winter rapeseed cultivars. For the early maturing winter rapeseed cultivars, the accumulation proportion of dry matter and phosphorus element was the largest in anthesis to silique stage, about 79.9%-80.0%, 69.3%-79.5% respectively, and the accumulation of nitrogen, potassium was the largest in anthesis, about 46.8%-47.7%, 39.9%-52.3% respectively. For the conventional mature winter rapeseed cultivars, the accumulation proportion of dry matter, phosphorus and potassium was the largest in the anthesis, about 37.1%-38.6%, 44.1%-49.3%, 32.8%-36.2% respectively, the maximum accumulation rate of nitrogen in seedling stage was about 48.6%-73.9%. Compared with the conventional mature winter rapeseed cultivars, the peak absorption of dry matter and nutrients by early maturing winter rapeseed cultivars was delayed, and the accumulation of dry matter and P, K nutrients was mostly concentrated in anthesis to silique stage. The nutrient accumulation of winter rape increased with the increase of dry matter accumulation. The growth period of early maturing winter rapeseed cultivars was 185d shorter than that of conventional mature winter rapeseed cultivars which lasted 200d, which could alleviate the contradiction of stubble during rice-rape rotation. The accumulation of nutrients of N and P in harvest period was significantly higher than that of conventional mature winter rapeseed cultivars, and the nutrient accumulation characteristics of N, P, K was suitable for slow and controlled release fertilizers. Because of the short growth period and high nutrient accumulation, there are seasonal advantages and nutrient accumulation advantages in planting early maturing winter rapeseed cultivars in the triple cropping area of the South China.