关键词: 生活型, 海拔, 养分状况, 水分利用效率

Abstract: This paper studied the variation patterns of soil labile organic carbon fractions and water stable aggregates in oasis cropland under effects of different long term fertilization treatments, which could have significance in evaluating oasis cropland soil quality and regional carbon cycle. The study was conducted on an oasis cropland in Xinjiang of Northwest China, and installed four treatments, i.e., long-term (20 years) abandoned cultivation, no fertilization, chemical fertilization, and chemical plus organic fertilization. Cultivation conduced to the accumulation of particulate organic carbon, dissolved organic carbon, dissolved inorganic carbon, and water stable macro-aggregates (>0.25 mm) in surface soil (0-20 cm). As compared with no fertilization, chemical plus organic fertilization more conduced to the accumulation of soil labile carbon fractions and the formation and stability of water stable macro-aggregates. In the same treatments, the particulate organic carbon and water stable macro-aggregates in surface soil played a dominant role to their accumulation throughout the soil profile, while the dissolved organic and inorganic carbon in surface soil had a contrast tendency. There was a significant positive correlation between the soil labile carbon fractions and aggregate stability.

Key words: elevation, life form, nutrient status., water use efficiency