Assessment of Four Techniques for Estimating Yield on Dryland Pastures1

Abstract

Information is limited on the suitability of short‐cut methods of yield assessment in low density pastures in marginal environments. Since this information would be of value to researchers working in such environments, four short‐cut, double sampling techniques were compared with hand clipping to assess their usefulness in estimating yield in large‐scale experiments located on low density, lucerne‐based (Medicago sativa L.) pastures. The methods included the measurement of pasture height (Method 1); percentage ground cover (Method 2); and a combination of Methods 1 and 2 assessed either by calculating the product (HG) of the direct measurement of the parameters (Method 3); and by utilizing a plywood board dropped on the pasture the height measurement of which effectively integrates pasture height and cover into a single expression (Method 4). Percentage ground cover was not correlated with yield and was considered unsuitable for predicting yield in this type of pasture. Significant correlations were apparent between yield and the parameters of height, and a combination of height and cover. Sampling variation is discussed in relation to the use of these techniques. All techniques (excluding percentage ground cover) possessed sufficient sensitivity to distinguish yield differences in grazed lucerne pasture. The board technique, the most sensitive, required 53% less time than the others in data collection than clipping.