.:: Lao Knowledge Base on Conservation Agriculture ::.
Cropping systems
How to produce more biomass for direct seeding mulched ... Featured
In North Cameroon, from 2001 to 2006, more than 250 farmers tried direct seeding mulch-based cropping systems (DMC) in their fields. DMC systems were based on farmer traditional rotation i.e. cereal//cotton. Farmers compared on their own field cereals (maize, sorghum, millet) cultivated with conventional techniques and the same cereal conducted with DMC techniques i.e. : i) intercropped with a cover crop (Mucuna pruriens, Brachiaria ruziziensis, Crotalaria retusa, Vigna unguiculata, Dolichos lablab); ii) sowed without ploughing from the first or the second year of experimentation. Associations were made for reaching the following objectives: i) produce aboveground biomass to produce mulch for the following crop (mainly cotton); ii) improve the soil’s physical and chemical quality through the contribution of associated plants; iii) produce forage; iv) help to control weed, v) protect the soil surface against erosion and rain impacts; vi) produce grains for consumption by humans or animals. Each of the 5 ...
Read More...
No till corn/soybean systems Featured
The analyzed soil physical properties analyzed were: water-aggregate stability (WAS), bulk density (Db), penetration resistance (PR), total porosity (TP), pore-size distribution, water retention properties, and saturated hydraulic conductivity (Ksat). The experimental design was a split-split-plot where whole-plot treatments (sampling period) had a Latin square design and subplot treatments (crop sequences) were arranged in a randomized complete block design with four replications. Compared with winter fallow, crop sequences that included WCC provided substantial benefits from the soil productivity standpoint. Specifically, the use of the C-R/S-V or C-R/S-VR increased SOM down to 30 cm. All WCC sequences improved WAS with increases of 9, 13, and 17% for C-R/S-R, C-R/S-V, and C-R/S-VR, respectively. Winter cover crop sequences reduced Db and PR of the soil surface and increased total and storage porosity along with plant available water. While the C-R/S-V sequence was the most effective in reducing soil NO ...
Read More...
Competitiveness of Semidwarf Upland Rice Cultivars agai... Featured
The use of winter cover crops (WCC) such as hairy vetch (Vicia villosa Roth) and cereal rye (Secale cereale L.), in a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation provides long-term benefits that are generally overlooked. There is a particular lack of information regarding the effects of WCC on soil physical and chemical properties. The objective of this study was to assess the effects of four crop sequences (C/S, corn-fallow/soybean-fallow; C-R/S-R, corn-rye/soybean-rye; C-R/S-V, corn-rye/soybean-vetch; and C-R/S-VR, corn-rye/soybean-vetch and rye) under no-till on several soil physical and chemical properties. Soil chemical properties included soil organic matter (SOM), pH, total nitrogen (TN), nitrates (NO3–N), and available phosphorus (P). When savannas in Latin America are brought into cultivation, rice (Oryza sativa L.) can be sown with the perennial grasses palisadegrass [Brachiaria brizantha (Hochst. ex A. Rich) Stapf] and signalgrass (B. decumbens Stapf) to harvest a grain cro ...
Read More...
Sustainable crop rotations with cover crops Featured
Cover crops offer many benefits for agriculture that include erosion control; reduced compaction and nutrient leaching; increased water infiltration; improved soil biodiversity; weed control and disease suppression; increased carbon sequestration and maximum nutrient recycling; improved air, soil, and water quality; and wildlife enhancement. Every cover crop species has its own niche and attributes for agricultural production. A wrong combination of cover crops may exert negative attributes, so a thorough understanding of cover crops selection and management is needed to minimize negative outcomes.
Cover Crop Management and Nitrogen Rate in Relation to ... Featured
Cover crop management in no-tillage systems prior to planting the principal crop can be an important tool in maximizing the beneficial effects of the cover crop on the principal crop. A field experiment was conducted in 1984 and 1985 to examine timing effects of cover crop desiccation relative to corn planting [early desiccation/early plant (EE), early desiccation/late plant (EL), and late desiccation/ late plant (LL)] and fertilizer N (0, 100, and 200 kg ha–1) on corn growth and yield. These management schemes were evaluated for fallow, rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), and hairy vetch (Vicia villosa Roth.) cover crop systems. Corn dry matter production and N uptake, monitored in all 0 kg N ha–1 treatments, were significantly affected by cover crop management and varied according to stage of development and climatic conditions. Cover crop type had a pronounced effect on corn growth, with corn dry matter production in a rye cover crop lower than in legume cover crops. ...
Read More...
Short-term green manure and tillage management effects ... Featured
Andisols are very important land resources supporting high human population density. Maize (Zea mays L.) production on Andisols located in the Purhepecha Region of central Mexico is representative of the highlands conditions of Mexico and Latin America. Farmers struggle with low crop yield and low soil nutrient availability. A 2-year field study was conducted to evaluate the effects of green manures either tilled into the soil (CT) or cut and left on the surface as a mulch (ZT), on maize yield and soil quality. Green manure treatments were: vetch (Vicia sativa L.), oat (Avena sativa L.) and none. No extra N was added to maize. Green manure and tillage had a significant effect on maize grain yield, N uptake and P uptake with CT vetch performing better than ZT oat. Soil organic C and total N were significantly higher under ZT than under CT management. Soils with vetch had higher P concentration. Soil under ZT oat had the highest infiltration rate and penetration resistance compared with other treatments. Th ...
Read More...
Fourteen years of applying zero and conventional tillag... Featured
Soil management systems may negatively affect the quality of the soil. Policymakers and farmers need scientific information to make appropriate land management decisions. Conventional (CT) and zero tillage (ZT) are two common soil management systems. Comparative field studies under controlled conditions are required to determine the impact of these systems on soil quality and yields. The research presented studied plant and soil physical and chemical characteristics as affected by different agricultural management practices, i.e. ZT and CT, cropped with continuous wheat or maize in monoculture (M) or in a yearly rotation (R) of these two crops, either with residue retention (+r) or without residues retention (−r), in an experimental field in the Transvolcanic Belt of Mexico after 14 years. The dominant factors defining soil quality were organic C, total N, moisture, aggregate stability, mechanical resistance, pH and EC. The principal component combining the variables organic C, total N, aggregate stabil ...
Read More...
Direct seeding on plant cover with "soil smouldering" t... Featured
The soils in hilly and densely populated areas in the “Hautes-Terres” region of Madagascar are mainly ferrallitic and thus fragile, relatively infertile and prone to erosion. In addition, under low temperature conditions, organic matter breaks down very slowly and traps nutrients that are essential for crops. Direct seeding systems on plant cover offer a broad range of benefits, including erosion control and soil fertility enhancement. However, yield improvements are low because farmers —focusing chiefly on their immediate survival— apply very little fertilizer. Facing these constraints, soil smouldering, associated with direct seeding on vegetal cover, should allow a sustainable improvement of the production, with minimum inputs.
Developing sustainable cropping systems with minimal in... Featured
The soils in hilly areas in thé Hautes-Terres region of Madagascar are mainly ferrallitic and thus fragile and relatively infertile. In addition, under low température conditions, organic matter breaks down very slowly and traps nutrients that are essential for crops (Chabanne, Seguy & Razakamiaramanana, 1996). Saturation of lowland rice growing areas and high population pressure is leading to accelerated conversion of these hilly areas into cropland. Bush fires and successive ploughing bas led to severe soil erosion, silting of rice fields and destruction of agricultural development projects. Direct seeding systems on plant cover offer a broad range of benefits, including erosion control and soil fertility enhancement (Rakotondralambo & Razanamparany, 1998). However, yield improvements are low because farmers-focusing chiefly on their immediatesurvivalapply very little fertilizer.
| © 2009 ORCATAD Project, Nafri Organization |  |
 |
 |