ROTATION IN CONSERVATION AGRICULTURE SYSTEMS OF ZAMBIA: EFFECTS ON SOIL QUALITY AND WATER RELATIONS

2010 ◽  
Vol 46 (3) ◽  
pp. 309-325 ◽  
Author(s):  
C. THIERFELDER ◽  
P. C. WALL
Keyword(s):  
Soil Moisture ◽  
Soil Quality ◽  
Cover Crop ◽  
Green Manure ◽  
Conservation Agriculture ◽  
Crop Rotations ◽  
Water Infiltration ◽  
Total Carbon ◽  
Control Treatment ◽  
Positive Effects

SUMMARYConservation agriculture (CA) systems are based on minimal soil disturbance, crop residue retention and crop rotation. Although the capacity of rotations to break pest and disease cycles is generally recognized, other benefits of crop rotations in CA systems are seldom acknowledged and little understood. We monitored different conventional and CA cropping systems over the period from 2005 to 2009 in a multi-seasonal trial in Monze, southern Zambia. Both monocropped maize and different maize rotations including cotton and the green manure cover crop sunnhemp (Crotalaria juncea) were compared under CA conditions, with the aim of elucidating the effects of crop rotations on soil quality, soil moisture relations and maize productivity. Infiltration, a sensitive indicator of soil quality, was significantly lower on conventionally ploughed plots in all cropping seasons compared to CA plots. Higher water infiltration rate led to greater soil moisture content in CA maize treatments seeded after cotton. Earthworm populations, total carbon and aggregate stability were also significantly higher on CA plots. Improvements in soil quality resulted in higher rainfall use efficiency and higher maize grain yield on CA plots especially those in a two- or three-year rotation. In the 2007/08 and 2008/2009 season, highest yields were obtained from direct-seeded maize after sunnhemp, which yielded 74% and 136% more than maize in the conventionally ploughed control treatment with a continuous maize crop. Even in a two-year rotation (maize-cotton), without a legume green manure cover crop, 47% and 38% higher maize yields were recorded compared to maize in the conventionally ploughed control in the two years, respectively. This suggests that there are positive effects from crop rotations even in the absence of disease and pest problems. The overall profitability of each system will, however, depend on markets and prices, which will guide the farmer's decision on which, if any, rotation to choose.

scholarly journals Use of Crop Rotations, Cover Crops and Green Manures for Disease Suppression in Potato Cropping Systems

2021 ◽  
Vol 8 ◽  
pp. 153-168
Author(s):  
Robert P. Larkin
Keyword(s):  
Disease Control ◽  
Microbial Activity ◽  
Cover Crops ◽  
Cover Crop ◽  
Green Manure ◽  
Cropping Systems ◽  
Crop Rotations ◽  
Disease Suppression ◽  
Green Manures ◽  
Rotation Crops

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.

Effect of integrated management of couch grass (Elytrigia repens) on soil quality and crop nutrition

1998 ◽  
Vol 130 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Y. K. SOON ◽  
A. L. DARWENT
Keyword(s):  
Microbial Biomass ◽  
Soil Quality ◽  
Green Manure ◽  
Integrated Management ◽  
Red Clover ◽  
Crop Rotations ◽  
Continuous Cropping ◽  
Soil N ◽  
Couch Grass ◽  
Elytrigia Repens

The effects of suppressing couch grass (Elytrigia repens L.), through integrated management, on soil biological quality and N and P nutrition of barley (Hordeum vulgare L.) were evaluated in a field experiment (1987–92) on a Dark Grey soil in Alberta, Canada. The management practices consisted of combinations of herbicide application, crop rotations and tillage treatments. The 3-year crop sequences consisted of continuous barley, canola (Brassica rapa L.)–barley–barley, fallow–barley–barley, and barley or canola undersown with red clover (Trifolium pratense L.)–red clover green manure–barley. In 1992, the sixth year of the experiment, soil and plant samples were analysed for nutrient content. Treatments that consisted of spring and autumn tillage only did not suppress couch grass and produced low barley yields and N and P uptake. More N was immobilized in couch grass shoots and rhizomes and soil microbial biomass with these treatments than with similar herbicide-treated crop rotations. Tillage-plus-herbicide treatments effectively suppressed couch grass and enabled the barley crop to compete for soil N, however, both spring and autumn tillage were required for weed control. The fallow treatment impaired soil quality by reducing soil and microbial C and N, but produced similar barley yields as continuous cropping with tillage-plus-chemical control. Red clover ploughed in for green manure enhanced soil quality indicators such as soil and microbial biomass C, total and mineralizable soil N, and microbial N, but did not increase barley yield compared to continuous grain cropping.

Weed emergence as affected by maize ( Zea mays L.)-cover crop rotations in contrasting arable soils of Zimbabwe under conservation agriculture

2016 ◽  
Vol 81 ◽  
pp. 47-56 ◽  
Author(s):  
Blessing Mhlanga ◽  
Stephanie Cheesman ◽  
Bhagirath Singh Chauhan ◽  
Christian Thierfelder
Keyword(s):  
Zea Mays ◽  
Cover Crop ◽  
Zea Mays L ◽  
Conservation Agriculture ◽  
Crop Rotations ◽  
Arable Soils ◽  
Weed Emergence

scholarly journals On-farm Assessments of Pasture Rejuvenation Methods on Soil Quality Indicators in Northern Alberta (Canada)

2018 ◽  
Vol 7 (2) ◽  
pp. 74 ◽  
Author(s):  
Akim Omokanye ◽  
Calvin Yoder ◽  
Lekshmi Sreekumar ◽  
Liisa Vihvelin ◽  
Monika Benoit
Keyword(s):  
Soil Quality ◽  
Infiltration Rate ◽  
Fertilizer Application ◽  
Water Infiltration ◽  
Control Treatment ◽  
Soil Conditions ◽  
Forage Production ◽  
Manure Application ◽  
On Farm ◽  
Northern Alberta

The study was aimed at providing livestock producers with options on practical methods to improve soil quality of pastures for improved forage production and livestock carrying capacity. The study was carried out on-farm from 2015 to 2017 at two sites in northern Alberta, Canada. The methods of rejuvenation (treatments) evaluated were: sub-soiling, break & re-seed (pasture renewal), a combination of manure application plus subsoiling, pasture rest, inorganic fertilizer application, high stock density grazing and bale grazing. A check/control treatment was included for comparison. For break & re-seed, the forage mixture seeded (16.8 kg ha-1) consisted of 60% grasses and 40% legumes. Overall, bale grazing improved soil organic matter (SOM) by up to 3.80% over other methods including check. In terms of soil compaction penetration resistance, water infiltration rate, water content and nutrients particularly N, P and K, bale grazing system as a method of rejuvenating old pastures significantly showed higher values than check at both sites. Without having to break and re-seed old pastures, the first option that livestock producers would have success with in improving soil quality for better pasture productivity would be bale grazing. The next two methods or rejuvenation strategies with great potential for improving soil conditions for pastures would be a combination of manure application plus subsoil in fall and high stock density grazing. 

scholarly journals Utilisation of Cover Crops: Implications for Conservation Agriculture Systems in a Mediterranean Climate Region of South Africa

2021 ◽  
Author(s):  
Ernst H. Smit ◽  
Johann A. Strauss ◽  
Pieter Andreas Swanepoel
Keyword(s):  
South Africa ◽  
Triticum Aestivum ◽  
South African ◽  
Soil Quality ◽  
Spring Wheat ◽  
Cover Crops ◽  
Cover Crop ◽  
Mediterranean Climate ◽  
Conservation Agriculture ◽  
Agriculture Systems

Abstract PurposeCover crops can provide multiple agroecosystem services to crops produced in conservation agriculture systems. South African grain producers in the Mediterranean climate region are reluctant to integrate cover crops in rainfed systems since cover crops replace cash crops leading to financial losses. Using cover crops as fodder can help cover input costs, while providing a range of advantageous services to the cropping system. The aim of this study was to investigate how cover crop mixtures and the utilisation of cover crops affect soil quality, the quality and quantity of the mulch as well as wheat (Triticum aestivum L.) produced in the subsequent year.MethodsA two-year study was conducted in the Western Cape Province of South Africa. In Year 1, diverse legume and cereal-based cover crop mixtures were partially grazed, cut and material removed for haymaking, or left unutilised as a mulch. In Year 2, spring wheat (Triticum aestivum L.) was planted to investigate the effects of cover crop mixtures and utilisation method on subsequent spring wheat yield. ResultsCover crops used as hay or for grazing did not affect (P < 0.05) grain yield of wheat that followed in rotation. Legume-based cover crop mixtures increased (P < 0.05) wheat grain protein content regardless of utilisation method. Soil quality and nitrogen content improved (P < 0.05) when cover crops were grazed. ConclusionsCover cropping can be used by South African grain producers as an important agronomic tactic to improve system productivity and support sustainable intensification of rainfed cropping systems.

Conservation agriculture in Southern Africa: Advances in knowledge

2014 ◽  
Vol 30 (4) ◽  
pp. 328-348 ◽  
Author(s):  
Christian Thierfelder ◽  
Leonard Rusinamhodzi ◽  
Amos R. Ngwira ◽  
Walter Mupangwa ◽  
Isaiah Nyagumbo ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Southern Africa ◽  
Crop Residues ◽  
Crop Yields ◽  
Conservation Agriculture ◽  
Crop Productivity ◽  
Soil Disturbance ◽  
Crop Rotations ◽  
Water Infiltration ◽  
Soil Parameters

AbstractThe increasing demand for food from limited available land, in light of declining soil fertility and future threats of climate variability and change have increased the need for more sustainable crop management systems. Conservation agriculture (CA) is based on the three principles of minimum soil disturbance, surface crop residue retention and crop rotations, and is one of the available options. In Southern Africa, CA has been intensively promoted for more than a decade to combat declining soil fertility and to stabilize crop yields. The objective of this review is to summarize recent advances in knowledge about the benefits of CA and highlight constraints to its widespread adoption within Southern Africa. Research results from Southern Africa showed that CA generally increased water infiltration, reduced soil erosion and run-off, thereby increasing available soil moisture and deeper drainage. Physical, chemical and biological soil parameters were also improved under CA in the medium to long term. CA increased crop productivity and also reduced on-farm labor, especially when direct seeding techniques and herbicides were used. As with other cropping systems, CA has constraints at both the field and farm level. Challenges to adoption in Southern Africa include the retention of sufficient crop residues, crop rotations, weed control, pest and diseases, farmer perception and economic limitations, including poorly developed markets. It was concluded that CA is not a ‘one-size-fits-all’ solution and often needs significant adaptation and flexibility when implementing it across farming systems. However, CA may potentially reduce future soil fertility decline, the effects of seasonal dry-spells and may have a large impact on food security and farmers’ livelihoods if the challenges can be overcome.

scholarly journals Conservation agriculture systems for Malawian smallholder farmers: long-term effects on crop productivity, profitability and soil quality

2012 ◽  
Vol 28 (4) ◽  
pp. 350-363 ◽  
Author(s):  
Amos Robert Ngwira ◽  
Christian Thierfelder ◽  
Dayton M. Lambert
Keyword(s):  
Soil Quality ◽  
Smallholder Farmers ◽  
Cultural Beliefs ◽  
Conservation Agriculture ◽  
Maize Yield ◽  
Crop Productivity ◽  
Conventional Tillage ◽  
Production Costs ◽  
Water Infiltration ◽  
Gross Margins

AbstractConservation agriculture (CA) systems are based upon minimal soil disturbance; crop residue retention and crop rotation and/or intercrop association are increasingly seen to recycle nutrients, increase yield and reduce production costs. This study examines the effects of CA practices on crop productivity, profitability and soil quality under the conditions encountered by smallholder farmers in two farming communities from 2005 to 2011 in Malawi, as part of the contribution to remedy a lack of supporting agronomic research for these relatively new systems. The drier agroenvironment of Lemu of Bazale Extension Planning Area (EPA) is characterized by sandy clay loam soils and lower rainfall. Here, CA showed positive benefits on maize yield after the first season of experimentation, with highest increases of 2.7 Mg ha−1 and 2.3 Mg ha−1 more yield in CA monocrop maize and CA maize–legume intercrop, respectively, than the conventional tillage in the driest season of 2009/10. In the high rainfall environment of Zidyana EPA (characterized by sandy loam soils), substantial maize yield benefits resulted in the fifth season of experimentation. Farmers spent at most 50 days ha−1 (US$140) producing maize under CA systems compared with 62 days ha−1(US$176) spent under conventional tillage practices. In Lemu, both CA systems resulted in gross margins three times higher than that of the conventional control plot, while in Zidyana, CA monocrop maize and CA maize–legume intercrop resulted in 33 and 23% higher gross margins, respectively, than conventional tillage. In Zidyana, the earthworm population was highest (48 earthworms m−2 in the first 30 cm) in CA monocrop maize, followed by a CA maize–legume intercropping (40 earthworms) and lowest (nine earthworms) in conventionally tilled treatment. In both study locations CA monocrop maize and CA maize–legume intercrop gave higher water infiltration than the conventional treatment. Improvements in crop productivity, overall economic gain and soil quality have made CA an attractive system for farmers in Malawi and other areas with similar conditions. However, for extensive adoption of CA by smallholder farmers, cultural beliefs that crop production is possible without the ubiquitous ridge and furrow system and residue burning for mice hunting have to be overcome.

scholarly journals Response of Pecan Orchard Soil Chemical and Biological Quality Indicators to Poultry Litter Application and Clover Cover Crops

HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 306-310 ◽  
Author(s):  
M. Lenny Wells
Keyword(s):  
Phosphatase Activity ◽  
Soil Quality ◽  
Cover Crop ◽  
Poultry Litter ◽  
Biological Indicators ◽  
Inoculum Potential ◽  
Cool Season ◽  
Positive Effects ◽  
Crimson Clover ◽  
Orchard Soil

Little information is available regarding the activity of soil quality biological indicators in southeastern U.S. pecan [Carya illinoinensis (Wangenh.) K. Koch] orchards. The objectives of this study were to examine the effect of poultry litter application and the use of crimson clover (Trifolium incarnatum L.) as a cool-season cover crop on soil chemistry and soil quality biological indicators, including mycorrhizal inoculum potential (MIP), microbial biomass carbon (MBC), and phosphatase activity in a southeastern U.S. Coastal Plain pecan orchard system. The use of clover as a cool-season cover crop between tree rows provided multiple benefits for pecan orchard soil quality, including increased MIP and MBC. Soil phosphatase activity was also enhanced by clover during two of the three years of study. Soil elemental properties, including total nitrogen (N), and soil organic matter (SOM) were also enhanced by clover and/or poultry litter, although there was an obvious time lag in the response of soil N to the treatments. Poultry litter application increased soil phosphorus (P) but did not consistently enhance soil biological activity parameters. At times, poultry litter appeared to neutralize or minimize the positive effects of clover on MIP.

Sign in / Sign up

Export Citation Format

Share Document