【摘要】 本文研究了一定吸力范围(1—15巴)内三种粘重土壤的破碎模数与湿度的关系,结果表明,砖红壤、红壤和下蜀黄土的破碎模数转折湿度分别为25.3%(干土%,下同),15.3%和15.7%。与它们的水分特征曲线对照研究表明,取8巴吸力的对应湿度作为破碎模数转折湿度,与实测值相比误差均小于1%。参照已经发表的14条典型的水分特征曲线估算,以8巴吸力的对应湿度作为破碎模数的转折湿度,对绝大多数土壤来说其误差可小于2%。由于破碎土块需施的压力在破碎模数转折湿度这一点上开始显著增加,因此它可以作为适耕下限的一个参数。更多还原

【Abstract】 The relationship between modulus of rupture and moisture content of three clayey soils within a suction range of 1—15 bars was studied. The results showed that the turning points of moisture content for rupture modulus of latosol, red earth and yellow earth were 25.3%, 15.3% and 15.7% respectively. According to the characteristic curves of these soils, taking the moisture contents of the soils at 8 bar as the critical values of the turning point, their errors were less than 1% (dry weight percent) as compared with the measurements. As compared with other 14 typical characteristic curves published in literature, it is suggested that this critical value would be suitable for most soils with the errors less than 2% (dry weight percent). Owing to the turning point of the moisture content for modulus of rupture at which the pressure to break down the soil clod increases signifieantly, this critical value of soil moisture content could be considered as a parameter for the lower limit of soil tillage.更多还原