Root development in some common New Zealand pasture plants

Summary Pure species of three grasses and two clovers were sown on a soil of low aggregate stability. The plots were sampled at intervals for root yields and for soil aggregate analyses. Wet sieving was used to measure aggregate stability. The grasses produced more fibrous roots than the clovers, and the soils from the grass plots had a higher aggregate stability. The Warburg Respirometer was used to determine the rate of decomposition of dead roots in moist soil. There was a significant positive correlation between root decomposition and the resultant aggregate stability of the soils used. The relationship between root characteristics and aggregate stability is discussed.