棉花、大豆、油菜关键生育期排渍指标研究

INDEXES OF SUBSURFACE WATERLOGGING TO BE ELIMINATED IN A KEY GROWTH STAGE OF COTTON,SOYBEAN AND RAPE

棉花、大豆和油菜是江汉平原广泛栽培的旱地作物,由于北亚热带季风气候的影响,在作物生长季节通常有较多降水,使作物遭遇持续受渍胁迫,引起产量下降。为了探索作物持续受渍情况下的排水管理,利用田间小区和大型测坑进行了3种作物关键生育期持续受渍试验。结果表明,持续受渍对旱作物产量有明显影响,受渍程度越严重,作物产量越低;受渍程度SEW30与相对产量Ry之间具有显著的线性负相关关系。以地下水超标水位累积值SEW30作为受渍程度指标,按照减产10%～15%作为尺度,提出了3种作物关键生育期的排水控制指标:棉花花铃期为80～120cm·d,夏大豆花荚期为150～200cm·d,油菜花果期为80～120cm·d。

Cotton, soybean and rape are upland crops popularly cultivated in Jianghan plain. A plentiful rainfall in crops growing season due to influence from northern subtropic monsoon climate makes crops suffered from subsurface waterlogged stress and causes crop yield reduction. In order to explore crop drainage management in case of continuous subsurface waterlogging, the continuous waterlogged test of the 3 crops in key growth stage was carried out in field plots and trial pits. The results showed that the crop yield was obviously affected when crop is in status of continuous subsurface waterlogging, the more serious the subsurface waterlogging is, the much more effection crop yield was resulted. There was a notable linear negative correlation between the degree of crop suffering from subsurface waterlogging called SEW\-\{30\} and relative yield Ry. Regarding the sum of excessive soil water table namely SEW\-\{30\} as the index of waterlogging degree,according to the standard of 10%～15% yield reduction,the drainage control index was given in key growth stage of the 3 crops, that is 80～120 cm·d for cotton in flowers and bolls stage, 150～200 cm·d for summer soybean in flowers and pods stage, 80～120 cm·d for rape in flowers and pods.