Effect Of Irrigation On The Evapotranspiration Of Turf And Characteristics Of Nutrient Requirement Of Turfgrass Species

The experiment studied the growth specialty, visual estimates, evaportranspiration and characters of nutrient requirement of six turfgrass species in two water condition to resolve the problem of fertilization and irrigation in turf managementThe results indicated: The clipping yields of the warm-season turf are more than those of the cool-season turf, Buffalograss has the most clipping yield and Perennial Ryegrass has the least one in both water conditions. At the same time, The clipping yields of turf in full irrigation condition is more than those in unfull irrigation condition, but they have no significant difference. The water content of turf has no significance in two water conditions, but different turf species have significantly different (PO.05), the cool-season turf is more than the warm-season turf.The cool-season turf has two fast growth period in its procreate period, the faster growth is in May, the other is in September. Buffalograss, one of the warm-season turf has two equally fast growths too, but one is in June, the other is in August. Both Bermudagrass and Japanese Lawngrass have one fast growth period in the middle of August.The quality of turf varies with season, the cool-season turf behaves better in spring and august, and the warm-season turf behaves better in summer, but it has no significant difference in two water condition.The evapotranspiration of turf changes regularly with season, the same season turf has the same development trend. The cool-season turf has the most evapotranspiration in May while the warm-season turf in August.The evapotranspiration of the warm-season turf is more than that of the cool-season turf. The most discrepancy is 198.7mm/m2' growth season. In the whole procreate period, the evapotranspiration of turf from most to least as followed: Tall Fescue> Kentucky Bluegrass> Perennial Ryegrass> Bermudagrass> Buffalograss> Japanese Lawngrass.The evapotranspiration of turf is affected heavily by water condition, and the evapotranspiration of turf in full irrigation condition is more than that in unfull irrigation51condition significantly (PO.05). In other words, saving water can be obtained by unflull irrigation.According to ET0 which is obtained by the climate model "ETCAL" the researcher calculated the KC of turf, the Kc of warm-season turf is between 0.66-0.92 and the K^ of cool-season turf is between 0.93-1.14, so they are very close to the KC of other general crops in north china.On the foundation of the evapotranspiration got from the experiment, eliminating the precipitation of a year in Beijing, it concluded the complement water in thesis in turfgrass management is from 298.22 mm/m2*growth season to 610.27 mm/in2'growth season in unfull irrigation condition. Tall Fescue needs the most complement water and Japanese Lawngrass needs the least one.The assimilation to different nutrient of turf has significant difference (PO.05). The concentration of nutrients in turf tissue is different, the most is nitrogen, the second is potassium, and the third is phosphors. The total P in turf tissue has significantly different in two water condition (P<0.05), but the total nitrogen and potassium has no signicant difference.