摘要
在模拟田间原状土容重的条件下土培,研究了土壤水分和氮磷营养对小麦根苗生长及水分利用的效应。结果表明:在SRWC为40％～70％范围内,土壤水分亏缺严重,Rr_w和ET显著降低,根苗生长严重受阻,RL变短,RDW降低,LA和PDW减少;随着土壤水分趋于良好,Rr_w、ET和LA明显增加,RDW和PDW在SRWC为55％～62％之间时最大,而SRWC在55％上下时RL达最长;土壤轻度干旱有利根系下扎,土壤水分趋于良好有利于根量增长。磷营养可显著提高Rr_w、RL、RDW、ET、LA、PDW和WUE,在严重干旱条件下磷对R7_w、RL、WUE的调节效果更好。氮素营养对小麦根苗生长的效果与磷相比有明显差别。土壤严重干旱,氮营养引起RX_w、ET和LA的明显下降,为负效应;轻度干旱氮对R审_w,ET和LA无明显作用;在土壤水分良好条件下,氮对R审_w、ET和LA具有显著的正向调节效果。随着SRWC的提高,增施氮磷肥可引起RDW和PDW的显著增加。磷除作为营养物质促进作物根苗生长发育外,它在增强作物抗旱性方面的作用更为重要。在旱地农业生产中,不可忽视对磷营养的使用。
2 pot experiments each with 6 treatments and 8 replications were conducted in order to study the effects of soil moisture, nitrogen and phosphorus supplied on root and seedling growth of wheat. A wheat cultivar Xiaoyan 6 was used. Results showed that under soil relative water content (SRWC) 40%-70%, as SRWC decreasing, root and seedling growth of wheat are inhibited, root water potential (Rw), leaf area (LA), evapo-transpiration (ET), root length (RL), root dry weight (RDW) and plant dry weight (PDW) are obviously declining. SRWC increases, Rw LA and ET increase obviously, but RL, RDW and PDW is a curve response, the maximun can be reached when SRWC is 55%-62% for RDW and PDW, and 55% for RL, respectively. Nitrogen and phosphorus supplied have very fine adjustment effect on root and seedling growth of wheat. Phosphorus can remarkably raise Rw, RL, RDW, ET, LA, PDW and WUE, especially under the condition of serious water stress. The effect of nitrogen is different from that of phosphorus. Under serious water stress with nitrogen supplied, Rw, ET and LA decrease, showing negative action; but no obvious action under light drought, and positive action under soil water enough. It is of benefit to RDW and PDW to enhance application of nitrigen and phosphorus as SRWC increasing. Phosphorus supplied can strenghten droughtre-sistance of wheat seedling, therefore, it must be taken into account in upland field.
出处
《作物学报》
CAS
CSCD
北大核心
1996年第4期476-482,共7页
Acta Agronomica Sinica
基金
国家自然科学基金
关键词
根苗
土壤水分
氮
磷
营养
小麦
Root and seedling
Soil water
Nitrogen and phosphorus nutrition
Wheat
