Soil microbial and biochemical characteristics in relation to soil management and fertility

Long-term impacts of de-oiled two-phase olive mill waste on soil chemical properties, enzyme activities and productivity in an olive grove

“…According to those authors, the protection of enzymes by humic-like substances could explain the high levels of ARS activity shown by DW-amended soils in the residual year. Positive relationships between soil enzyme activities and crop yields are to be expected (e.g., Ferná ndez et al, 2009;Verstraete and Voest., 1977). In our study however, olive yields were only significantly correlated with UR (r = 0.579, P < 0.05), and PHO (r = 0.520, P < 0.05).…”

Supplementing chemical fertilizer with an organic component increases soil biological function and quality

“…Their results showed that compared with CK, organic manure increased soil invertase and urease activities by 108.4% and 136.1%, respectively. Verstraete and Voets (1977) showed that application of animal manure plus green manure over a 7-year period substantially increased diphosphatase, urease, saccharase and b-glucosidase activities. These findings, along with the results of this study, are supported by a range of other studies also showed that addition of organic matter to soils results in increased soil microbial functional diversity and enzyme activity over chemical fertilizer (e.g., Marinari et al, 2000;Bending et al, 2004).…”

Interpretation of Microbial Soil Indicators as a Function of Crop Yield and Organic Carbon

“…Because crop yields can be influenced by numerous factors that are not related to soil quality, such as climate, plant genotype, and the occurrence of pests and diseases, correlations between the microbial indicators and crop yield are not often found in the literature (Verstraete and Voets, 1977;Dick et al, 1988;Hungria et al, 2009). We attribute the high correlations obtained in the present study to the unique opportunity identified in these longterm field experiments where: (i) in the 24 selected treatments, the management of P fertilizers made it possible to modulate the crop yields (Fig.…”