Impact of conservation agriculture on soil health: lessons from the university of fort hare trial.

2022 ◽  
pp. 293-304
Author(s):  
Lindah Muzangwa ◽  
Isaac Gura ◽  
Sixolise Mcinga ◽  
Pearson Nyari Mnkeni ◽  
Cornelius Chiduza

Abstract Conservation Agriculture (CA) promotes soil health, but issues to do with soil health are poorly researched in the Eastern Cape, South Africa. This study reports on findings from a field trial done on the effects of tillage, crop rotations composed of maize (Zea mays L.), wheat (Triticum aestivum L.) and soybean (Glycine max L.) and residue management on a number of soil health parameters such as carbon (C)-sequestration, CO2 fluxes, enzyme activities, earthworm biomass and the Soil Management Assessment Framework soil quality index (SMAF-SQI). The field trial was done in a semi-arid region of the Eastern Cape Province, South Africa, over five cropping seasons (2012-2015). It was laid out as a split-split plot with tillage [conventional tillage (CT) and no-till (NT)] as main plot treatment. Sub-treatments were crop rotations: maize-fallow-maize (MFM), maize-fallow-soybean (MFS); maize-wheat-maize (MWM) and maize-wheat-soybean (MWS). Residue management: removal (R-) and retention (R+) were in the sub-sub-plots. Particulate organic matter (POM), soil organic carbon (SOC), microbial biomass carbon (MBC) and enzyme activities were significantly (p < 0.05) improved by residue retention and legume rotation compared to residue removal and cereal-only rotations. Also, carbon dioxide (CO2) fluxes under CT were higher compared to NT. The calculated soil quality index (SQI) was greatly improved by NT and residue retention. MWM and MWS rotations, in conjunction with residue retention under NT, offered the greatest potential for building soil health. Residue retention and inclusion of soybean in crop rotations are recommended for improving soil health under CA systems in the semi-arid regions of South Africa.

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 576
Author(s):  
Sixolise Mcinga ◽  
Lindah Muzangwa ◽  
Kudzayi Janhi ◽  
Pearson Nyari Stephano Mnkeni

Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects of conservation agriculture (CA) principles on earthworms under the semi-arid climate of the central Eastern Cape (EC) of South Africa (SA) are limited. Therefore, this study investigated the effects of tillage, crop rotations, and residue management on earthworms’ abundance and species richness. The study design followed a split-split plot with three replicates. The main plot was allocated to tillage treatment, which had conventional tillage (CT) and no-tillage (no-till) as factors. Crop rotation treatment was allocated to a subplot, and had maize (Zea mays)–fallow–maize (MFM), maize–fallow–soybean (Glycine max) (MFS), maize–wheat (Triticum aestivum)–maize (MWM), and maize–wheat–soybean (MWS). Residue management was in the sub-subplot with residue retention and residue removal. The study was carried out over four cropping seasons: summer 2015–2016, winter 2016, spring 2016, and summer 2016–2017. The results showed that the genera Amynthas and Lumbricus, both belonging to the anecic group, and Dendrobaena, belonging to the epigeic group, were present. Earthworm species diversity and density were highest under no-till than under CT. Residue retention improved earthworm density regardless of tillage management. Rotations that had fallow periods recorded lower earthworm numbers as compared to continuous cropping systems where wheat was grown in winter. The study concluded that maize–wheat–soybean (MWS) rotation with residue retention results in the highest earthworm abundance and species richness.


2018 ◽  
Vol 6 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Bibek Thapa ◽  
Keshab Raj Pande ◽  
Baburam Khanal ◽  
Santosh Marahatta

A field experiment was conducted to evaluate the effect of tillage practices, residue management and cropping system on soil properties at NMRP, Rampur, Chitwan from November 2015 to April 2016. The experiment was laid on Strip split design with combination of 12 different treatments i.e, zero tillage & conventional tillage as main plot in the strip, residue retention & residue removal as sub-plot factor and maize – wheat, maize + soybean – wheat & soybean – wheat cropping system as sub-sub plot factor. Three replications of the treatments were made. Soil sample before experiment and after harvest of wheat was taken (0-15cm). The experiment showed significant effect of zero tillage on organic carbon (2.169%) and on total soil nitrogen (0.112 %). Zero tillage with retention of residues is valuable tool for the conservation agriculture and helps in sustainability of soil however long-term research for the tillage management and residue retention should be conducted to highlight the major effects on change in properties of soil.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 164-168 


2020 ◽  
Vol 13 (22) ◽  
Author(s):  
Solomon Temidayo Owolabi ◽  
Kakaba Madi ◽  
Ahmed Mulakazi Kalumba ◽  
Israel Ropo Orimoloye

AbstractTheme unsuitability is noted to have inhibited the accuracy of groundwater potential zones (GWPZs) mapping approach, especially in a semi-arid environment where surface water supply is inadequate. This work, therefore presents a geoscience approach for mapping high-precision GWPZs peculiar to the semi-arid area, using Buffalo catchment, Eastern Cape, South Africa, as a case study. Maps of surficial-lithology, lineament-density, drainage-density, rainfall-distribution, normalized-difference-vegetation-index, topographic-wetness-index, land use/land cover, and land-surface-temperature were produced. These were overlaid based on analytical hierarchical process weightage prioritization at a constituency ratio of 0.087. The model categorizes GWPZs into the good (187 km2), moderate (338 km2), fair (406 km2), poor (185 km2), and very poor (121 km2) zones. The model validation using borehole yield through on the coefficient of determination (R2 = 0.901) and correlation (R = 0.949) indicates a significant replication of ground situation (p value < 0.001). The analysis corroboration shows that the groundwater is mainly hosted by a fractured aquifer where the GWPZs is either good (9.3 l/s) or moderate (5.5 l/s). The overall result indicates that the model approach is reliable and can be adopted for a reliable characterization of GWPZs in any semi-arid/arid environment.


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