Residual effects of fallows on selected soil hydraulic properties in a kaolinitic soil subjected to conventional tillage (CT) and no tillage (NT)

Improved fallows have been used to reduce time required for soil fertility regeneration after cropping in low input agricultural systems. In semi-arid areas of Southern Africa, Acacia angustissima and Sesbania sesban are among some of the more widely used improved fallow species. However the residual effects of improved fallows on soil hydraulic properties during the cropping phase is not known. The aim of this study was to quantify the residual effects of fallows and tillage imposed at fallow termination on soil hydraulic properties (infiltration rates, hydraulic conductivity and soil porosity) during the cropping phase. Treatments evaluated were planted fallows of Acacia angustissima, Sesbania sesban and natural fallow (NF) and continuous maize as a control. Steady state infiltration rates were measured using a double ring infiltrometer and porosity was calculated as the difference between saturated infiltration rates and tension infiltration measurements on an initially saturated soil. Unsaturated hydraulic conductivity (K-o) and mean pore sizes of water conducting pores were measured using tension infiltrometer at tensions of 5 and 10 cm of water on an initially dry soil. While there was no significant difference in steady state infiltration rates from double ring infiltrometer measurements among the fallow treatments, these were significantly higher than the control. The steady state infiltration rates were 36, 67, 59 and 68 mm h(-1) for continuous maize, A. angustissima, S. sesban and NF respectively. Tillage had no significant effect on steady state infiltration rate. Pore density at 5 cm tension was significantly higher in the three fallows than in maize and varied from 285-443 m(-2) in fallows, while in continuous maize the pore density was less than 256 m(-2). At 10 cm tension pore density remained significantly higher in fallows and ranged from 4,521-8,911 m(-2) compared to 2,689-3,938 m(-2) in continuous maize. Unsaturated hydraulic conductivities at 5 cm tension were significantly higher in fallows than in continuous maize and were 0.9, 0.7, 0.8 cm and 0.5 cm h(-1) for A. angustissima, S. sesban, NF and continuous maize, respectively. However there were no significant treatment differences at 10 cm tension. Fallows improved infiltration rates, hydraulic conductivity and soil porosity relative to continuous maize cropping. Through fallowing farmers can improve the soils hydraulic properties and porosity, this is important as it affects soil water recharge, and availability for plant growt

Soil organic carbon dynamics of improved fallow-maize rotation systems under conventional and no-tillage in Central Zimbabwe

Fallowing increases soil organic carbon (SOC) during the fallowing phase. However, this benefit is lost quickly during the cropping phase. The objective of this study was to evaluate SOC dynamics of an improved fallow-maize rotation under no-tillage (NT) and conventional tillage (CT) from time of fallow termination, through the next two cropping seasons. The treatments studied were improved fallows of Acacia angustissima (A. angustissima) and Sesbania sesban (S. sesban), natural fallow and continuous maize. Our hypothesis is that fallowing maintained higher SOC and lower soil bulk densities through the cropping phase when compared with continuous maize system and that NT maintained higher SOC when compared with CT. Soil organic carbon was significantly greater under fallows than under continuous maize from fallow termination to the end of the second cropping season. Soil organic carbon for the 0¿5 cm depths was 11.0, 10.0, 9.4 and 6.6 g kg¿1 for A. angustissima, S. sesban, natural fallow and continuous maize, respectively at fallow termination. After two cropping seasons SOC for the same depth was 8.0, 7.0, 6.1, 5.9 g kg¿1 under CT and 9.1, 9.0, 8.0, 6.0 g kg¿1 under NT for A. angustissima, S. sesban, natural fallow and continuous maize, respectively. Total SOC stocks were also higher under fallows when compared with continuous maize at fallow termination and after two cropping seasons. Soil bulk densities were lower under fallows when compared with continuous maize during the period of study. We concluded that fallows maintained greater SOC and NT sequestered more SOC than CT. Acacia angustissima was the better tree legume fallow for SOC sequestration when compared with S. sesban or natural fallow because it maintained higher SOC and lower bulk densities after two seasons of maize cropping

Causes of wildland fires and factors that influence knowledge of fire management at Crofton village, Makoni district, Zimbabwe

Wildland fires are a threat to the conservation of biodiversity and human life. In Zimbabwe, the newly re-settled smallholder farmers are perceived as the major drivers of wildland fires. A survey was conducted in Crofton Village Ward 38 of Makoni District in Zimbabwe to determine farmers’ knowledge on the causes of wildland fires and factors that influence their knowledge on the management of wildland fires. Randomised purposive multistage sampling was used to select 60% of the total population in the study area. Data processing and analysis was done using the Statistical Package for the Social Sciences (SPSS) version 21.0 of 2012 to analyse the relationship between the dependent variable (farmers’ knowledge of wildland fire management) and independent variables (sex, age, level of education and period of stay in the village. Farmers revealed that land clearing, poor disposal of ashes, brick moulding and arson were the chief causes of wildland fires. There was a significant (p<0.05) relationship between period of stay in the village with farmer’s knowledge of management of wildland fires. Farmers’ knowledge on wildland fire management was influenced by period of stay and exposure to wildland fires in the village. Farmers with a longer period of stay in the study area were more knowledgeable than those with a shorter period. Gender and age had an effect on farmer’s knowledge about causes of wildland fires and men apparently had more knowledge and experience with wildland fire management. Human activities were responsible for most of the wildland fires. Resettled farmers, farmers with primary level and those with no formal education had limited knowledge on wildland fire management.  It was recommended that effective wildland fire awareness programmes be put in place to improve farmer knowledge and wildland fire management skills

Challenges faced in controlling wildland fires in Mazowe A1 resettlement farming areas of Zimbabwe

Wildland fires pose a big threat to both flora and fauna. In Zimbabwe an estimated 1 million hectares (ha) are burnt annually. The present study uses multiple sources of information including review of published literature, reports, field observations, questionnaires and interviews to investigate the challenges faced in controlling wildland fires in A1 resettlement farming areas of Zimbabwe. Two sites, ward 24 and 31 in Mazowe District were used as case studies to compile responses from 400 households. The results of the study indicated that issues of education, experience and lack of information in wildland fire management played a role in wildland fire management. In ward 24.6% never attended school, while 30%, 48% and 8% had reached primary education, secondary education and tertiary education respectively.  In ward 31, the highest level of education of the respondents was 8%, 58% and 34% for primary level, secondary level, and tertiary education respectively. The predominant challenge was lack of experience in fire control as 52% of the respondents had never been involved in fire suppression. In addition, lack of information was highlighted as a major cause of wildland fires, as only 35% of respondents had attended fire awareness campaigns. The other challenges included; lack of proper fire fighting equipment, poor volunteerism and poor implementation of policies and regulations. It was concluded that multiple challenges exist in managing wildland fires, and hence more emphasis should be placed in training and equipping communities with fire management skills and provision of fire fighting equipment. A multi-sectoral approach is also recommended for implementation and enforcement of fire management regulations in the resettlement farming areas

Formulating finger millet (Eleusine coracana L) and cowpea (Vigna unguiculata) food blend for enhanced micronutrients for children below 5 years

Malnutrition of children under 5 years is a public health concern because it is the most vulnerable stage of child’s growth where its impact results in long term health conditions such as stunting, wasting, obesity and poor cognitive development. This study aimed at developing a Rapoko-Cowpea porridge blend to enhance dietary micronutrients among children below the age of 5 years and assess its sensory acceptability. A mixed methods research approach was adopted consisting of a quasi- experiment and a cross sectional survey. Vendors from Mbare market were clustered based on the source of their finger millet and cowpea grains (Masvingo, Murewa, Gokwe). A Completely Randomised Design (CRD) was used with three treatments (blends) replicated three times. Proximate analysis was done using standard AOAC methods. Compared to cowpea, finger millet had the highest levels of carbohydrates (78.12g/100g), iron (8.7mg/100g), zinc (3.77mg/100g). Results also show that 75:25. Rapoko-Cowpea blend ratio had the ability to meet WHO daily nutrient requirements for children under the age of 5 years. Blend ratio of Rapoko: cowpeas (75:25) had the highest carbohydrates (69.41g/100g), protein (25.64g/100g), zinc (1.74mg/100g), iron (5.14mg/100g), energy (411.37kcal), and vitamins (0.11 mcg RAE) with RaCoB1 blend having the lowest nutrient composition. Results have showed that finger millet (Rapoko), cowpeas and RaCoB (Rapoko-Cowpea blend) blends have high macro and micronutrients (iron and zinc) to support daily nutritional requirements of children below the age of 5 years and may help in addressing malnutrition. Sensory evaluation was done with 100 panellists from the University of Zimbabwe and of the three blends, a 75:25 ratio was the most preferred (90.88%). Further studies need to analyse the effects of anti-nutritional factors, bioavailability of nutrients, shelf life of the food blend and commercialization potential of RaCoB blends. The government is therefore encouraged to provide agronomic support for increased productivity of small grains and pulses through improved research and extension. There is a need to develop a policy at national level that promotes blending of cereals and pulses as well as innovative small scale food processing initiatives through private-public partnerships.http://ajfand.netAnthropology and Archaeolog

Community perceptions towards the establishment of an urban forest plantation: a case of Dzivaresekwa, Zimbabwe

The health of urban forest communities not only depend on the government and nongovernmental organizations, but also strongly rely on local community stewardship. A study was carried out to assess community perceptions on the establishment of an urban forest plantation among urban residents in Dzivaresekwa, an urban area in Harare. Randomized systematic sampling was used to select 150 households and one resident per household was interviewed using a pretested questionnaire with both closed and open-ended questions. The objectives of the study were to determine how age and gender and employment status variables, were related to the urban residents perceptions towards establishment of a forest plantation in an urban area. Most females (58.3%) viewed the plantation as a threat while most men (51.7%) viewed the plantation as a recreational area. The highest proportion (61.9%) of the middle age group (21-40 years) perceived the plantation as a source of employment. There was a statistically significant relationship (p = 0.040) between gender and the general perception of establishing a forest plantation in the urban area. However, there was no statistically significant relationship (p = 0.203) between age groups and the perception of establishing a forest plantation in the urban area. It is concluded that the community had diverse perceptions on urban community forestry. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.20973 Int. J. Agril. Res. Innov. & Tech. 4 (1): 16-23, June, 201

Maize yields under coppicing and non coppicing fallows in a fallow–maize rotation system in central Zimbabwe

Fallowing can improve crop yields as a result of improved soil fertility and nutrient status. The objective of this work was to determine the effects of fallows and pruning regimes in coppicing fallows on soil moisture and maize yields under conventional tillage (CT) and no tillage (NT). Fallows that were evaluated were coppicing Acacia angustissima, non coppicing Sesbania sesban, natural fallow (NF) and continuous maize. In 2000/2001 season, maize yields were significantly different (P continuous maize > NF > A. angustissima, for both CT and NT. The 2-week pruning regime had significantly higher maize yields when compared to the 1 and 3 week pruning regime during the 2002/2003 cropping season. For the three seasons, CT had significantly higher yields than NT. A. angustissima had significantly higher mean available water at suctions 33 kPa for all treatments. It was concluded that improved fallowing increased yields when compared to NF. However, in coppicing fallows competition for water can result in reduced yields when there is rainfall deficiency, thus the need for pruning to manage the competition

Infiltration and runoff losses under fallowing and conservation agriculture practices on contrasting soils, Zimbabwe

Fallowing and conservation agriculture are sustainable farming practices that can be used for soil and water conservation. The objectives of the study were to evaluate the effects of different conservation agriculture practices on rainfall infiltration and soil and water losses across 4 sites, using simulated rainfall. The study was carried out at Domboshawa and the Institute of Agricultural Engineering and Chikwaka smallholder farming areas, 4 sites with different soil types. Conservation agriculture practices evaluated were mulch reaping (MR) and clean reaping (CR) at Domboshawa with 5% clay and the Institute of Agricultural Engineering (IAE) with 50% clay. The study also evaluated runoff losses from fallow plots subjected to no tillage (NT) and conventional tillage (CT) at ICRAF Domboshawa site (20% clay) and fallows subjected to CT in Chikwaka smallholder farming areas (4% clay). Infiltration rates were greater under conservation agriculture practices (>35 mm∙h -1 ) when compared to CT (<27-29 mm∙h -1 ). On fallows infiltration rates ranged from 24-35 mm∙h -1 when compared to <15 mm∙h -1 in maize under CT. Runoff losses were highest under CT at both Domboshawa and IAE sites, and were 21.5 and 15% respectively, while there was no runoff under MR and CR. At the ICRAF Domboshawa site, runoff ranged between 0-31% in fallows and was 57% in maize under CT. At Chikwaka runoff in CT maize was 58%, while in fallow plots runoff ranged 37-44%. Soil losses ranged from 0.2-0.3 t∙ha -1 per rainfall event in maize, while in fallows, soil loss ranged from 0-0.1 t∙ha -1 . The results showed that CT resulted in reduced infiltration rates, increased soil and water loss when compared to fallowing and conservation agriculture across different range of soils. Conservation agriculture practices and fallowing are potential sustainable cropping practices that reduce soil and water loss and increase water use efficienc

Opportunities for optimization of in-field water harvesting to cope with changing climate in semi-arid smallholder farming areas of Zimbabwe

Climate change has resulted in increased vulnerability of smallholder farmers in marginal areas of Zimbabwe where there is limited capacity to adapt to changing climate. One approach that has been used to adapt to changing climate is in-field water harvesting for improved crop yields in the semi- arid regions of Zimbabwe. This review analyses the history of soil and water conservation in Zimbabwe, efforts of improving water harvesting in the post independence era, farmer driven innovations, water harvesting technologies from other regions, and future directions of water harvesting in semi arid marginal areas. From this review it was observed that the blanket recommendations that were made on the early conservation method were not suitable for marginal areas as they resulted in increased losses of the much needed water. In the late 1960 and 70s', soil and water conservation efforts was a victim of the political environment and this resulted in poor uptake. Most of the water harvesting innovations which were promoted in the 1990s' and some farmer driven innovations improved crop yields in marginal areas but were poorly taken up by farmers because they are labour intensive as the structures should be made annually. To address the challenges of labour shortages, the use of permanent in-field water harvesting technologies are an option. There is also need to identify ways for promoting water harvesting techniques that have been proven to work and to explore farmer-led knowledge sharing platforms for scaling up proven technologies

Burning, biomass removal and tillage effects on soil organic carbon and nutrients in seasonal wetlands (Dambos) of Chiota smallholder farming area, Zimbabwe

Seasonal wetland (dambo) cultivation in smallholder farming areas is important because it improves household food security. However, most farming practices, such as burning of vegetation and conventional tillage in dambo gardens, may reduce soil organic carbon (SOC) and nutrient dynamics. We evaluated the effects of simulated burning, vegetation clearing and clipping, and conventional tillage in dambo gardens on SOC, nutrient contents and biomass production over a 3-year period. The results showed that clearing and clipping of vegetation and conventional tillage reduced SOC, soil nutrient contents and biomass yields, while burning increased SOC and soil nutrient contents. For the 0–10 cm depth, conventional tillage, clearing and clipping resulted in a 37%, 34% and 18% decrease in SOC, respectively, after three seasons, burning resulted in a 25% increase in SOC, while there were no changes in the control after 3 years. For the 0–40 cm depth, the average change in SOC was 32%, 25% and 16% for conventional tillage, clearing and clipping, respectively. Locally and regionally, conventional tillage, clearing and clipping reduce SOC, nutrient contents and biomass production in dambos. Though annual burning increased SOC and nutrient contents in the short term, the long-term effects are uncertain, hence there is a need for long-term studies