Micro-Distribution of Trifolium Repens L. and Its Relation to Soil Factors

Abstract

The relationship between micro-distribution of T. repens (white clover) and soil factors was investigated by(i) widespread sampling in a 130 km2 area by paired soil samples from Agrostis-Festuca swards with T. repens and adjacent swards without T. repens (mean distance 75 cm),(ii) intensive concurrent sampling of T. repens cover and soil in a 100 m2 area. Over distances of 60 cm soil Ca, phosphate and K varied by as much as a factor of 3 and pH by 0.7 units. In widespread sampling T. repens was associated with higher levels of pH and Ca, and to a lesser extent phosphate. In local sampling T. repens was associated with higher levels of Ca, and possibly also phosphate, but not with pH. The relationship between T. repens cover and soil Ca was sigmoid, the form of response to fertilizers on very deficient soils. The importance of recognizing wide soil variability in ecological studies and soil sampling is stressed.