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The consequences of climate change threaten existing agriculture systems across Zimbabwe. The researchers examined the possibility and potential for developing a smallholder farmer driven macadamia nuts value chain. Using the case of Chipinge district, Manicaland province, Zimbabwe, the study evaluated the potential of macadamia nut value chain functions as a climate change resilience strategy in Zimbabwe. Challenges faced by actors and positive developments made in incorporating smallholders into the macadamia nuts production sector were explored. The role of local markets and producers in the international trade in macadamia nuts were also examined, using a modified stakeholder analysis framework. Triangulation, a mixed methodology, was used to adequately capture the various quantitative and qualitative dimensions along the macadamia nuts value chain pillars. A sample of 220 farming units including Estates, A1 and A2 farmers was proportionately selected for the study. Primary data were collected from Key Informants through interviews and personal communications. Secondary data were collected from Agritex officers, buyers, and the Macadamia Association of Zimbabwe farmers’ records. The production-marketing interface for macadamia nuts is weakly coordinated in the study area as shown by the rudimentary production systems especially for the A1 and A2 farmers. Results show that the major missing links are the limited application of extension driven production enhancers and the limited visibility of farmers in more rewarding export markets. Production scales have, however, been increasing with more farmers allocating land towards the macadamia nuts trees. Decentralization of macadamia nuts markets and localized value addition needs to be done to realign domestic and export market prices.

The study aims to map areas sensitive to erosion by water and rainfall erosivity after addition of organic matter (OM) in highly unstable soils. A soil association map was created using digital soil mapping methodology. Soil samples from six soil associations were incubated and analysed for several soil erodibility measures and inferred to the soil association map. Soil stabilization against soil erosion by use of OM was evaluated for 30 weeks under two simulated rainstorms, intermittent rainstorms (IR) and single rainstorm (SR). Rainfall erosivity (R-factor) was calculated from theduration of a rainstorm and the total amount of rainfall received under rainfall simulations. Erodibility factor (K-factor) was estimated using the soil OM content and texture. Largest area (40%) was covered by shallow soils and K-factor range of 0.0693-0.0778 t.ha.hha-1MJ-1mm-1. Largest (60.2%) area had a structural stability index of 0.8 and 42.7% of the area was covered by a dispersion ratio value range of 0.65-0.70. The area size with erosion rates of > 15 t/ha/yr was drastically reduced from 1 to 8 weeks after OM application thereafter gradually increased under both IR and SR. Soil erosion rates of < 5 t-1 ha-1 yr-1 and > 15 t-1 ha-1 yr-1 were most and least observed respectively under both storms. R-factor was higher under IR than SR and the smallest areas with soil erosion rates of > 15 t-1 ha-1 yr-1 contributed most to the lost soil. Organic matter confers soil resistance to erosion up to a certain period before losing its effectiveness. The study provided first assessment of erosion dynamics, basis for identifying conservation priorities which may be applicable in similar areas. Keywords: Erosivity, planning, rainstorm, soil conservation, soil degradation

Performance of three newly released short-seasoned (Nsinjiro, Chitala and JL11) were evaluated against old (Nyanda, Illanda and Tern) groundnuts varieties under same agronomic practices. A field experiment laid in a randomized complete block design (RCBD) with three replicates was done. Varieties were evaluated for days to 50% emergence, 50% flowering, days to physiological maturity, pod and seed yield, and shelling percentage. There were no significant difference in the days to 50% emergence among all varieties but significant difference (p ˂ 0.05) were observed on days to 50% flowering. JL11 and Tern took shortest (90 days) and longest (120 days) time to physiological maturity respectively. Chitala had highest (3.804t/ha) and Tern had lowest (3.020t/ha) seed yield. Jl11 had highest (83%) and Nyanda least (68%) shelling percentage. Results showed that the new varieties out-performed the old varieties in all measured parameters. Therefore, resource constrained farmers may safely opt for the new short-seasoned varieties over the old ones.

Mixing different types of organic matters to form a compound compost can be useful in both short-and long-term improvement of soil chemical properties. However, effects of such composts on soil chemical properties are unknown. A 3-year field study was done to determine the effects of eucalyptus wood-based compost on selected chemical properties of soils at Mooketsi and Politsi avocado orchards, Limpopo Province, South Africa. The study was laid as a repeated measures design with 4 compost treatments at 0, 5, 10, and 15 t ha-1 year-1 with three replicates. Soil pH, EC, organic carbon, active carbon, soil NO3-N, NH4-N, PMN, P K, Ca, Mg, Na Mn, Cu, Zn, and Fe were measured annually at the two orchards after applying compost at the different rates. The eucalyptus wood-based compost significantly (p-1 and 0t ha-1 in 2018 respectively but with no significant (p>0.05) differences between 10t ha-1 and 15t ha-1 compost application rates the entire study period. Eucalyptus wood-based compost raised values of the soil chemical properties at ≥10t ha-1 application rates. It is recommended to apply the eucalyptus wood-based compost ≥10t ha-1 at both orchards, nevertheless, other factors governing organic matter decomposition such as soil temperature were not measured hence further studies are necessary.

Sources of fertilizer are one of the major factors influencing baby spinach leaf texture, sweetness, bitterness and after-taste. However, the effects of fertilizer sources on baby spinach growth performance and consumer preferences are not known. A survey was carried out at the Seke Teachers’ College (SKC) community, Zimbabwe to determine the consumer preferences on the baby spinach grown on the organic fertilizer (cattle, poultry and goat manures) as well as on control inorganic fertilizers (7% N, 14% P, 7% K). The study used 32 females and 30 males as panellists for sensory evaluations. Organoleptic tests were performed for the baby spinach leaves using a panel of 62 testers. An interval line scale (16 cm long) was used to measure the liking for sweetness, colour, bitterness and after-taste. A 9-point hedonic scale was used to decide the overall preferences. Organoleptic tests showed significant differences (P

Climate change and variability is already reducing agricultural productivity and opportunities for employment, pushing up food prices and affecting food availability and production of formerly adapted crop types. Such is the case in cotton production in Zimbabwe, where it was the only viable commercial crop in marginal areas. As a form of adaptation, there is need for African farmers to have a range of agricultural techniques as coping strategies and tactics to enable sustainable production of crops and deal with extreme events. Such techniques include water conservation and introduction of new adapted crop genetics to cope with the new environment. The emerging trends in climate change will force farmers to adopt new crops and varieties and forms of agricultural production technologies. The objective of this study is to determine the contribution of combining in-field water harvesting and early maturing cotton varieties in curbing drought in cotton in semiarid Zimbabwe. The results show that both water harvesting in form of planting basins significantly (P P

Chenopodium quinoa Willd (quinoa) is a crop that originated from the Andes and has been recently introduced in Zimbabwe so the agronomic performance is unknown yet. A 3-year field experiment was carried out at the Women’s University in Africa research farm, Marondera, Zimbabwe. The research evaluated the response of quinoa to different cattle manure application rates, plant population ha−1 and growing seasons. A 3 × 3 × 2 factorial in a completely randomized block design with three replicates was used in the experiment. Cherry Vanilla Quinoa variety was established under three cattle manure application rates (0, 9 and 18 t ha−1), three planting densities (29629, 55555 and 80 000 plants ha−1) and two growing seasons per year (summer and winter). Analysis of variance was done to compare the effects of the treatments on quinoa growth parameters. There was significant (P

Soil texture influences the transformation of soil organic matter (SOM), and depletion and reduction in the number of macroaggregates. However, the extent of changes in SOM in response to its quality and mechanisms of stabilization in different types of soil texture is unclear. We evaluated changes in SOM during a 30‐week incubation experiment using seven soils mixed with two sources of litter; Vachellia karroo (Hayne) Banfi & Galasso leaf and Zea mays L. stover. We hypothesized that changes in intraparticulate organic matter (iPOM) are influenced by litter quality • soil type • time interactions, which affect rates of turnover of macroaggregates. A completely randomized design was used in arranging soil jars in the incubator. Free light fractions and coarse and fine iPOM within macroaggregates (>250 μm) decreased exponentially from week 1 to 30 and were significantly (P

The resilience of soils under varying litter quality is unclear. Therefore, this study investigated the effects of different litter sources on soils with low ( 0.05) effects within a soil type. An increase in macroaggregation increased MWD, WSSI values and large and small aggregates distribution. Aggregation was significantly higher in soils with higher clay content than sand content, suggesting that soil texture was highly influential to the litter effects on SA. We concluded that the rate of soil aggregate reformation was influenced by soil type × time interactions which determined the extent and dynamics of macroaggregation during the 30 weeks of incubation.

Organic litter stabilizes soil particles against the raindrop splash effect. To date, limited research has critically examined the effects of litter quality on soil aggregate detachment and soil organic carbon loss by raindrop splash impact. A study was conducted to determine the effects of different litter sources on quantity of splashed sediments and soil organic carbon (SOC) loss under simulated rainstorm patterns. Soils from seven sieved (< 0.25 mm) horizons mixed with either high-quality Vachellia karroo leaf (C/N = 23.8) and/or low-quality Zea mays stover litter (C/N = 37.4) were incubated in a laboratory for 30 weeks. Splashed sediments and SOC were measured at 1, 3, 8, 14, 23 and 30 weeks of incubation for each soil at 360 mm/h simulated rainfall intensity applied as either single 8-min rainstorm (SR) or 4 × 2-min intermittent rainstorms (IR) separated by a 72-h drying period. Organic litter significantly ( P < 0.05) reduced the splashed sediments up to 8 and 14 weeks under IR and SR storms, respectively, and thereafter gradually lost its stabilizing effect on soil aggregates. In order to maintain low quantities of splashed sediments, fresh litter has to be re-applied after this stage. Generally, 13% and 25% more sediments were splashed under IR than SR at 1, 3 and 30, and 8, 14 and 23 weeks after incubation, respectively. Litter quality effect on splash sediments varied across soil horizons but were the same within a soil horizon. Soil horizons with more clay than sand particles had lower quantities of sediments. The SOC loss was influenced by the initial SOC content and primary particle size distribution. Rainstorm pattern and initial SOC content were the main factors that influenced SOC loss. However, more rainstorm patterns should be investigated for these soils. Keywords: erosion, litter, particle, rainfall patterns, resistance, sediments

Soil erosion has serious off-site impacts caused by increased mobilization of sediment and delivery to water bodies causing siltation and pollution. To evaluate factors influencing soil erodibility at a proposed dam site, 21 soil samples collected were characterized. The soils were analyzed for soil organic carbon (SOC), exchangeable bases, exchangeable acidity, pH, electrical conductivities, mean weight diameter and soil particles’ size distribution. Cation exchange capacity, exchangeable sodium percentage, sodium adsorption ratio, dispersion ratio (DR), clay flocculation index (CFI), clay dispersion ratio (CDR) and Ca:Mg ratio were then calculated. Soil erodibility (K-factor) estimates were determined using SOC content and surface soil properties. Soil loss rates by splashing were determined under rainfall simulations at 360 mmh−1 rainfall intensity. Soil loss was correlated to the measured chemical and physical soil properties. There were variations in soil form properties and erodibility indic...

Soil erosion is a major land degradation problem in South Africa (SA) that has economic, social and environmental implications due to both on-site and off-site effects. High rates of soil erosion by water are causing rapid sedimentation of water bodies, ultimately leading to water crisis in SA. Lots of financial and human resources are channelled towards controlling of soil erosion but unfortunately with little success. The level of soil erosion in a particular area is governed by the site properties. Therefore, it is inappropriate to generalize data on soil erosion at a large-scale spatial context. The literature on soil erosion in SA classifies Eastern Cape Province as a high-erosion-potential area using data collected at a large-scale spatial context. Collecting soil erosion data at a large spatial scale ignores site-specific properties that could influence soil erosion and has resulted in failure of many traditional soil erosion control measures applied in the province. Moreover, scientific pr...

Effects of fire frequency on soil chemical properties in semi-arid savannahs are still unclear. A study was conducted on a long-term fire research trial in the semi-arid part of Eastern Cape Province, South Africa. The study aimed at determining the impact of outbreak on the soil properties by comparing the effect of different prescribed fire frequencies on pH, C, N, P, Ca, Mg, Cu, Zn, Mn, Na levels and C:N ratios. The treatments were no burn (control), sexennial, quadrennial, triennial, biennial and annual burns randomly laid in uniform blocks. A line intercept sampling technique was used in soil sampling from 0 to 75 mm depth for analysis. Fire burning frequencies had significantly varied effects on soil chemical properties (P

Soil properties are known to be influenced Soil Organic Matter (SOM) resident time. However, there is limited information on the interactive effects of SOM quality and soil moisture on SOC and Microbial Biomass Carbon (MBC) hence on soil losses. Therefore, this study investigated the effects of different organic matter and soil moisture in soils with low (

High cost of hybrid seed can affect food self-sufficiency. A study was conducted to investigate the structure, conduct and performance of the hybrid maize seed industry in Zimbabwe to determine whether the level of competition in the industry caused high and unstable prices. Primary data on the quantity of hybrid maize produced and/or marketed, pricing strategies and hybrid maize seed prices for the period 2011 to 2015 was collected using questionnaires administered to marketing managers of 10 seed houses involved in hybrid maize seed production and marketing in Zimbabwe as well as key stakeholders. The questionnaires were also used as interview guides for key informant interviews with production managers of respective seed houses. Secondary data were obtained from annual reports and technical bulletins of respective companies. The analysis involved respondent triangulation as well as triangulating the data from responses with secondary data in order to increase the convergent validity of the data. Descriptive statistics, ANOVA and trend analysis were used for data analysis. Results indicated that the hybrid maize seed industry in Zimbabwe is highly concentrated meaning that there is low competition. The study established that there may be tacit collusion in the pricing of hybrid maize seed in the form of dominant firm price leadership. The study showed that prices have not been stable for the period 2011 to 2015. It is recommended that the government should enact policies that; prohibit abuse of a dominant position, prohibit mergers which create or strengthen a dominant position and prohibit state aid that creates monopolies.

The jatropha plant was introduced to Zimbabwe in 1940. Until recently, jatropha production was mainly done by communal farmers in marginal areas of the country. Being a multipurpose tree, the jatropha plant was being used to produce soap, lubricants and in soil conservation. Due to the fuel crisis that gripped Zimbabwe over the last decade, there has been a move towards producing biodiesel to complement imported fossil fuel. There is potential to produce animal and plant protectants, and organic fertilizer from jatropha. The current utilization of the plant is limited by lack of a clear government policy, unfavorable selling prices and unavailable agronomic information. There is need for government to come up with a policy that encourages production, research and utilization of biofuels. Information on jatropha propagation should be made available, not only in English, but vernacular languages also. Research should be encouraged so that varieties that are higher yielding are produced.