A simulated erosion approach to assess rates of cattle manure and phosphorus fertilizer for restoring productivity to eroded soils

Abstract

Erosion has reduced soil productivity in many areas of the world. Eroded soils remain unproductive unless appropriate soil amendments are applied. This study compared the effect of cattle manure and phosphorus (P) fertilizer rates in the restoration of soil productivity at three levels of simulated erosion on three calcareous soils in southern Alberta, Canada. In spring 1992, an existing simulated erosion experiment was modified to examine the effect of four rates of cattle manure (0, 24, 48 and 72 Mg ha −1) and three rates of P (low, recommended, high) in restoring the productivity of three soils which had 0, 10 and 20 cm of topsoil removed to simulate non-, moderate and severe erosion. The sites were cropped to spring wheat ( Triticum aestivum L.) for up to four years. Crop yield response to manure was of the order severe erosion > moderate erosion > non-eroded, which suggests that greatest benefits are achieved by applying manure to the most severely eroded areas of the landscape. For example on one site (Lethbridge Dryland in 1992), application of 24 Mg ha −1 of manure increased grain yield by 0.58 Mg ha −1 on the severely eroded soil, 0.25 Mg ha −1 on the moderately eroded soil and 0.16 Mg ha −1 on the non-eroded soil compared to the non-manured treatments at each erosion level. High levels of soil NO 3-N after manure application were largely responsible for maintaining high crop yields and restoring soil productivity. Manure was a better compensator for soil erosion than P fertilizer, apparently, in part, because fertilizer P was immobilized by high levels of calcium carbonates in exposed surfaces after simulated erosion.