Abstract
<p>Conservation agriculture has been promoted in Zambia as a strategy to mitigate some of the negative effects arising from conventional tillage practices. Conservation agriculture offers several potential benefits on soil properties. However, these benefits and impacts vary across agro ecological regions and management practices. This study investigated changes, over time, associated with the practice of conservation agriculture in selected soil chemical, physical and biological properties, including an assessment of the effects on soil respiration, nodulation and biological nitrogen fixation in soya beans (<em>Glycine max </em>(L.) Merr). Six paired soil samples were collected from conservation agriculture and conventional tillage fields. Fields under conservation agriculture were 4, 7 and 16 years old while those under conventional tillage had been cultivated for over 18 years. Changes in soil properties due to conservation agriculture practice were determined using published laboratory procedures and compared using the paired t-test at 95% confidence level. The results indicated significantly higher soil pH, soil organic carbon, nodulation and biological nitrogen fixation under conservation agriculture than conventional tillage after seven years of practice. The study also showed significantly higher total porosity, soil microbial biomass, soil respiration and lower soil bulk density after sixteen years of practice. Based on these results, the practice of conservation agriculture has potential to improve crop productivity by improving the different aspects of soil fertility, the length of time before this is realized notwithstanding. Further studies that compare several conservation agriculture systems are recommended in other agro-ecological zones of the country to validate these findings.</p>
Highlights
Agricultural farming systems involving extensive tillage and removal or on site burning of crop residues have hastened, by as much as 2.6 times, the rate of soil erosion and degradation (Verhulst et al, 2010)
There was a general increase in Soil Organic Carbon (SOC) under conservation agriculture (CA) over time, while the reverse was true for CT (1.57 to 1.38)
All the CA soils had SOC amounts above the critical limit of 1.5% for crop productivity (Fairhurst, 2012), while only one CT soil was above that limit
Summary
Agricultural farming systems involving extensive tillage and removal or on site burning of crop residues have hastened, by as much as 2.6 times, the rate of soil erosion and degradation (Verhulst et al, 2010). This depletion of soil fertility has been associated with low productivity and subsequent decline in food security in Africa (Giller, Witter, Corbeels, & Tittonell, 2009). In Zambia, the practice of CA by smallholder farmers is characterised by the three principles including minimum tillage (ripping or permanent planting basins), crop residue retention by mulch or incorporation, legume crop rotation and input application in fixed planting stations (Haggblade & Tembo, 2003). Conservation agriculture fields are usually cropped alongside conventional tillage (CT) fields by some of the farmers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
