Enzymatic activity and mineralization of carbon and nitrogen in soil cultivated with coffee and green manures

Abstract

SUMMARYThere are great concerns about degradation of agricultural soils. It has been suggested that cultivating different plant species intercropped with coffee plants can increase microbial diversity and enhance soil sustainability. The objective of this study was to evaluate enzyme activity (urease, arylsulfatase and phosphatase) and alterations in C and N mineralization rates as related to different legume cover crops planted between rows of coffee plants. Soil samples were collected in a field experiment conducted for 10 years in a sandy soil in the North of Paraná State, Brazil. Samples were collected from the 0-10 cm layer, both from under the tree canopy and in-between rows in the following treatments: control, Leucaena leucocephala, Crotalaria spectabilis, Crotalaria breviflora, Mucuna pruriens, Mucuna deeringiana, Arachis hypogaea and Vigna unguiculata. The soil was sampled in four stages of legume cover crops: pre-planting (September), after planting (November), flowering stage (February) and after plant residue incorporation (April), from 1997 to 1999. The green manure species influenced soil enzyme activity (urease, arylsulfatase and phosphatase) and C and N mineralization rates, both under the tree canopy and in-between rows. Cultivation of Leucaena leucocephala increased acid phosphatase and arilsulfatase activity and C and N mineralization both under the tree canopy and in-between rows. Intercropped L. leucocephala increased urease activity under the tree canopy while C. breviflora increased urease activity in-between rows.Index terms: Soil enzymes, mineralization potential, green manure, mulching, nutrient cycling.(

Soil Quality in Relation to Forest Conversion to Perennial or Annual Cropping in Southern Brazil

“…The great difference in C MIN and N MIN among sites suggested differences in labile soil C org and N accumulated, due to soil management and crop species, as previously observed (Franzluebbers and Stuedemann, 2008;Balota and Chaves, 2010). A broad range of C MIN are reported in the literature, ranging from 2 to 70 μg C g -1 d -1 according to Franzluebbers (2009) who compiled data for 33 published studies.…”

The biological activities of β-glucosidase, phosphatase and urease as soil quality indicators: a review

“…These enzymes are not only available in dead cells, but may also be taken up on clays or integrated into humic substances. Enzymes play a vital role in agriculture and in nutrient cycling, in particular, since they are constantly being synthesized, accumulated, inactivated and decomposed in the soil (Balota and Chaves, 2010).…”

“…The choice to use enzymes to assess soil quality is based on their sensitivity to soil management, organic matter decomposition, and relative ease of analysis (Balota and Chaves, 2010). The determination of soil fertility and plant yield using a single enzyme activity has been proven to be inaccurate (Nannipieri et al, 2012).…”

Humic substances and its distribution in coffee crop under cover crops and weed control methods

“…In a previous study, at Miraselva, in the north of the state of Paraná, in a very clayey Dystropheric Red Latosol under the coffee crop cultivar Catuaí, it was noted that the use of leguminous species between coffee rows influenced microbial activity in rows and between rows in coffee plantations (Balota and Chaves, 2010).…”