Effects of the sowing date on the growth and development, yield formation and water use efficiency of pea in Agro-pastoral Ecotone | 播期对农牧交错带豌豆生长发育、产量形成和水分利用效率的影响

Chinese. 为探讨不同播种期对农牧交错带豌豆生长发育、产量形成和水分利用效率的影响,采用随机区组试验设计,分析了内蒙古武川地区豌豆在2010年4月28日、5月8日、5月18日、5月28日和6月8日5个播期下生育期、形态指标、产量形成和水分利用效率的变化情况。结果表明：1）6月份之前播种,播种期对豌豆全生育期日数无明显影响（120～122d）;但随播期推迟,营养生长期延长,生殖生长期缩短,生殖生长期在整个生育期中所占比例减小,4月28日播期最高为40%,6月8日播期最低为22%;2）随播期推迟,豌豆株高和叶面积增长迅速,营养生长前期水热充沛可缓解后期水热资源不足,地上部干物质在8月中旬后迅速积累,5月18日及其后播种的豌豆茎、叶所占比例分别达到51%和45%;3）随播期推迟（6月份之前）,豌豆植株含水率、产量和水分利用效率提高,4月28日和5月28日播种的豌豆植株含水率、鲜草产量和干草产量分别为61.7%,1 280和490kg/hm2及77.0%,2 700和760kg/hm2。但播期推迟到6月8日,豌豆鲜草和干草产量比5月28日播种的分别下降200和190kg/hm2,干草水分利用效率下降为2.69kg/（hm2.mm）。建议农牧交错带豌豆适宜播种期安排在5月下旬,产量和植株含水量可得到双效提升,以充分发挥其绿肥作物的优良特性。

English. In order to study the effects of different sowing dates on the growth and development,yield formation and water use efficiency（WUE） of pea,the changes of phenology,morphological index,yield formation and WUE of pea under five sowing-date treatments which were April 28（SE）,May 8（E）,May 18（M）,May 28（L） and June 8（SL） were compared using randomized block design based on field experiments in Wuchuan county of Inner Mongolia in 2010.The results showed from the following three aspects.1）The sowing date before June had no significant impact on the length of growing season（120-122 d）,but vegetative growing period was prolonged and reproductive growing period was shortened when the sowing date was postponed.Ratio of the reproductive growing period to the whole growing period was reduced,with 40% as the maximum under SE and 22% as the minimum under SL.2）As the sowing date was postponed,plant height and leaf area grew rapidly,sufficient water and heat resources during earlier vegetative growing period could alleviate the insufficient water and heat resources occurring at the later growing period.Aboveground dry matter accumulated rapidly after mid-August,the ratio of stem and leaf to the whole plant increased to 51% and 45% respectively under M,L and SL.3）As the sowing date was postponed,plant water content,yield（fresh and dry） and water use efficiency were increased.The plant water content,fresh yield and dry yield under SE and L were 61.7%,1 280,490 kg/（hm2）,and 77.0%,2 700,760 kg/hm2 respectively.When the sowing date was postponed to June 8,fresh and dry grass yield reduced by 200 and 190 kg/hm2 respectively compared to that on May 28,WUE of dry grass reduced to 2.69 kg/（hm2・mm）.As green manure crop,the appropriate sowing date of pea in Agro-pastoral Ecotone was recommended to be arranged in late-May,thus both of the yield and water content could be increased.