摘要
本论文以半湿润地区土垫旱耕人为土(褐土)为供试土样,应用长期通气培养法,研究了湿度和温度对0—90cm土壤剖面不同土层(每30 cm为1土层)氮素矿化的影响。每层土壤设11.0、15.0、19.0、23.0、27.0%5个土壤水分等级和8.0、16.0、24.03、2.0、40.0℃5个温度等级,共25个处理,在恒温培养箱中进行培养。培养期间分别在7、14、21、354、9、63和84 d取样测定矿化氮累积量。结果表明,不同土层土壤有机氮的矿化累积量均随温度、水分含量升高而增加,各土层增幅的大小顺序为0—30 cm>30—60 cm>60—90 cm。0—30 cm土层矿化氮是0—90 cm土层可矿化氮的主体,其矿化氮占67.9%。不同土层土壤氮素矿化过程不同:在培养期间0—30 cm土层氮素矿化量与培养时间符合线性关系,而30—60 cm和60—90 cm土层符合对数函数;不同土层氮素矿化速率k与含水量w间为直线关系,相关系数r在0.93以上,0—30 cm土层的k值对温度反应最为敏感,其次为30—60 cm土层,以60—90cm土层反应最小。总体上看,在较高温度培养条件下,随温度增加,土层越深,矿化速率增加越慢;温度和水分对不同土层土壤氮素矿化具有明显的正交互作用。对0—30 cm土层,在高温情况下水分效果更加突出;而对30—60cm和60—90 cm土层,温度效应比水分效果更加突出。
Aerobic incubation experiment was conducted with Eum-Orthic Anthrosols（Cinnamon soils）of sub-humid area to study the effects of temperature and water condition on soil N mineralization of 0-90 cm soil layer which was divided into three layers （each 30 cm thick）. Soil samples were incubated at different temperature of 8.0, 16.0, 24.0, 32.0, 40.0℃ in tubers, and water contents were adjusted to 11.0%, 15.0%, 19.0%, 23.0%, 27.0% （w/w）, sampling 7, 14, 21, 35, 49, 63, 84 days after incubation, respectively. The results showed that N mineralization accumulation quantity of all soil layers increased with the increase of temperature and water content, in the order of 0-30 cm 〉 30- 60 cm 〉 60-90 cm. Mineralizable N of the 0-30 cm soil layer was the major part, which accounted for 67.9 % of total amount in 0-90 cm soil layer. Every soil layer had different mineralization process： mineralization process of 0-30 cm soil layer could be described with linear equation and 30-60 cm and 60-90 cm soil layers with logarithm equation during incubation. Statistical analysis significant correlation was obtained between the soil N mineralization rate （k） and water content （w）, which correlation coefficient was above 0.93. It was found that soil N mineralization rate of 0-30 cm soil layer was most sensitive to temperature, 30-60 cm was less, and 60-90 cm was least. As a whole, under the condition of higher incubation temperature, the N mineralization rate would be shower with the increase of temperature and soil layer depth. Temperature and water content of soil had interactive effects on the quantity and rate of N mineralization. To 0-30 cm soil layer, the positive effect of moisture on N mineralization was more evident than temperature under the higher incubation temperature, while to 30-60 cm and 60-90 era, the effect of temperature was more evident.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2007年第1期8-14,共7页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金(30571116
30230230)
西北农林科技大学创新团队项目资助
关键词
土垫旱耕人为土
氮素矿化
温度
含水量
Eum-Orthic Antrosols
N mineralization
temperature
water content
