EFFETS À LONG TERME D’APPORTS DE FUMIER SOLIDE DE BOVINS SUR L’ÉVOLUTION DES CARACTERISTIQUES CHIMIQUES DU SOL ET DE LA PRODUCTION DE MAIS-ENSILAGE

Abstract

A long-term field experiment was initiated on a Neubois silty loam in 1978 in the county of Levis, Québec to study the changes in soil characteristics and silage corn yields following manure application. Solid beef cattle manure was incorporated without fertilizer every 2 yr in fall, at rates of 0, 20, 40, 60, 80 and 100 t ha−1. Even when significant differences were observed between treatments low corn yields were obtained from 1978 to 1984. These low yields were related to the low N, P and K recoveries from applied manure. For the 20 t ha−1 application rate, N. P and K recoveries from manure in the first year were 28, 7 and 1396, respectively. N, P and K recovery decreased with manure application rates. Corn yields increased progressively, but they achieved their maximum value (10–12 t ha−1 DM) only in 1985 and after three manure applications. This was due to the important residual effect of manure. Highly significant increases in N (7–64%), P (80–300%) and K (37–158%) as well as other nutrients were associated with manure applications. Manure application also significantly increased soil pH, CEC and organic matter. Average yearly increases of organic matter content were 0.06% and 0.16% for 20 to 40 t ha−1, respectively, and varied from 0.20 to 0.30% for the highest application rates (60–100 t ha−1). These improvements of soil properties constitute the "indirect effect" of manure. This study showed that percent recovery of N, P and K from solid cattle manure was generally low. Thus, manure should be mainly considered as an organic amendment.Key words: Solid cattle manure, corn silage, percent recovery, pH, mineral nutrients, cation exchange capacity, organic matter