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Tomato (Solanum lycopersicum L.) is one of the most popular and widely consumed vegetable crops all over the world. They play a vital role in human diet and good sources of vitamins and minerals. However, low soil fertility is a major challenge to vegetable crops production for growers in Africa. Soils in the arid and semi-arid regions like South Africa have little nutrient and mineral contents, which adversely affect plant growth and quality. Therefore, the objectives of the study were to determine the effects of sole and combined applications of Effective Microorganisms enriched compost, broiler manure and inorganic (NPK) fertiliser applications, on growth and yield of three tomato varieties and to assess the influence of the applied fertiliser on nutritional composition of three tomato varieties. Field experiments were conducted at Horticultural skill centre, University of Limpopo (Mankweng), and at Mphebatho farm, Apel, Limpopo province, South Africa. The experiment was laid out in a 7 x 3 split-plot design. Recommended amount of organic and inorganic fertilisers was used. The treatments were: control (without fertiliser application), NPK (2:3:4(30) at a rate of 200 N ha-1, 260 P ha-1 and 257 K ha-1, applied as N from Urea, P from superphosphate and K from potassium chloride (KCl), mineralised broiler manure (10 000 kg ha-1), ½ NPK + ½ broiler manure rates, EM enriched compost (14 m3 ha-1), ½ EM compost + ½ NPK rates, and ½ EM compost + ½ broiler manure rates. Three tomato varieties (Floradade, Roma and Moneymaker) seedlings were transplanted using standard spacing of 30 x 60 cm. Chlorophyll contents of leaves, biomass production, plant height, fruit number, stem diameter and branch number were determined after six weeks of transplanting and fortnightly thereafter. The interactions between tomato varieties and fertiliser materials with regard to plant height were not significant (P ≤ 0.05) at both sites (Apel and Mankweng). Average plant height (63.75 cm) obtain, DAFF Zero hunger

Phosphorus (P) deficiency has been reported in 30- 40% of global arable land, which poses a huge threat in potato production because of its critical role in the early vegetative development and tuber formation. The use of low cost ground phosphate rock (GPR) as an alternative P fertilizer source has gained recognition. Although GPR contains high P percentage, its direct application is less beneficial immediately due to its low reactivity which makes P unavailable for plant uptake. In this experiment, GPR was co-composted with cattle and poultry manure in order to enhance P acquisition by the potato crop. The aim of this study was to evaluate the potential of phosphocompost application as a cheaper alternative P-source for potato production. The experiment was conducted on Mondial and Valor… potato cultivars at the University of Limpopo Syferkuil Experimental farm in 2015 and 2016. Poultry (PM) and cattle manure (CM)-based phospho-compost mix ratios of 8:2 and 7:3 were applied at 0, 20, 40, 80 and 120 kg P/ha. The trial was laid out in a split plot arrangement fitted into a randomised complete block design with treatments replicated three times. Results indicated statistically significant effects of phospho-compost types on soil pH and available P content at both flowering and harvesting growth stages in 2015 and 2016 with the higher available P content found in the PM-based phospho-composts. In both seasons, highly significant differences in fresh and dry leaf samples among phospho-compost types were obtained. Highly significant season x compost type interaction effects were also recorded on leaf biomass as well as the 2015 tuber weight, with highest tuber weight obtained in plots that received PM7:3-based phospho-compost at 80 t/ha rate. Notwithstanding the non-significant effect of compost type on tuber yield in 2016, higher yield was obtained from PM8:2. Although the grading of tubers showed no significant response to phospho-compost application; the difference b, Potato SA and the National Research Foundation (NRF)

Two experiments were conducted at Ukulima Root Biology Centre, Waterberg district in Limpopo Province (24°32'58.1"S, 28°06'21.1"E) during 2013-2014 cropping season to select IBM population inbred lines with improved root whorl and stem diameter that can enable them to tolerate nitrogen and phosphorus stress. The experiments were laid out in a Split plot format based on a randomized complete block design with four replicates. The main plot factors were: nitrogen levels (low and high) and phosphorus (low and high), in the respective trials and maize inbred lines (MO345, MO034, MO001, MO199, MO031 and MO196) were in the sub plots. Traits investigated included shoot morphological traits (plant height, leaf area per plant, chlorophyll content, stem diameter, number of leaves), root architectural traits (Whorl angles, root area, average root density, number of adventitious roots, number basal roots, average lateral root length, lateral branching frequency, root top angle, root bottom angle, distance to the first lateral root) and dry biomass. Results showed morphological traits, root architectural traits and biomass were affected by nitrogen fertilizer. Those traits were greater under high nitrogen level. On the other hand nitrogen had no influence on stem diameter size variation and whorl distribution. Plant height, number of leaves and dry biomass were significantly different among the inbred lines. The interaction of inbred and nitrogen fertilizer level had significant effect on leaf width and leaf area per plant. The lowest leaf width was recorded on inbred MO345 under low nitrogen level, while the highest value was recorded on inbred MO345 under high nitrogen level. Inbred MO031 and MO199 had highest values of leaf area per plant under high nitrogen level and inbred MO345 had the lowest value under low nitrogen level. Inbred lines planted under high nitrogen level had relative advantage in leaf growth over inbred lines planted under low nitrogen level. The study show

Soil acidity is one of the abiotic stress factors that greatly limit the productivity of crops on farmers’ fields. A greenhouse study was carried out over two summer growing seasons to evaluate the effect of lime and phosphorus (P) application rates on the growth, yield and root attributes of a determinate cowpea variety on acid soil. The experiment was laid out as a 4x5 factorial arrangement with 4 replications. Treatment factors comprised of variable rates of Vaalburg dolomitic lime (0, 2, 4 and 6 t ha-1) and P (0, 15, 30, 45 and 60 kg ha-1) using single super phosphate, 10.5% P. The two treatment factors were combined resulting in a total of 20 treatment combinations. Data collected included cowpea growth parameters, crop phenology, yield attributes and root characteristics. While cowpea plants with no P application consistently gave the least plant height, stem diameter, number and length of trifoliate leaves, the 6 t ha1 lime rate appears to be completely disadvantaged for all measured parameters with generally lower values than in soil filled pots without lime application. Results showed that soil pH was increased with 6 t ha-1 lime application while soil electrical conductivity (EC), percent of organic matter (OM) and total organic carbon (TOC) were all increased with increasing P and lime rates. All measured cowpea growth attributes such as plant height, stem diameter, number of trifoliate leaves, and leaf area were significantly increased (p≤0.05) with increasing P and lime rates. During the two planting seasons, P and lime application resulted in reduced (p≤0.05) duration to flowering, pod formation and physiological maturity. The 6 t ha-1 lime application produced higher number of pods (2.50) compared to the other rates. Application rates of 45 kg P ha-1 and 6 t ha-1 of lime produced superior number of seeds per pod with high values of (13.71) and (12.85), respectively. However, cowpea root attributes namely number of nodules per plant, the third branchin, National Research Foundation (NRF) and Department of Agriculture, Forestry and Fisheries (DAFF)

There exists a considerable level of spatial variability in soil physical and chemical properties within the research block; and the soils are generally shallow. Of all the measured parameters, electrical conductivity, Bray-1 P, exchangeable potassium, calcium and sodium as well as extractable iron and zinc showed a huge percent of variation across the field. Soil variability maps indicated the degree of variability within the research block. The spatial variability of the characterized parameters was significant across the research block. A correlation study was conducted to investigate the relationship between the measured soil physical and chemical properties. Regular soil analyses should be conducted to avoid failure/delay of experiments. It is recommended that inputs such as irrigation and fertilizer application must be varied based on varying soil conditions across the research block., VLIR project 6 leaders

Cowpea (Vigna unguiculata L. Walp) is an important grain legume grown in many parts of the world mostly by smallholder (SH) farmers. Low soil phosphorus (P) and drought stress are major constraints to legume production and threaten food security. Root architecture is a spatial configuration of the root system which is influenced by moisture status and P uptake. A field experiment was conducted at Ukulima farm near Modimolle in Waterberg district during 2012/13 summer growing season. The treatments comprised of two levels each for soil P (low and high) and moisture status (water stress and well-watered); and eight cowpea genotypes (Tvu 4632, Tvu 6365, Tvu 9848, Tvu 15445, Tvu 16408, Tvu 15143, Oloyin and IT00K-1217). The low P level implied the available P in the soil measured in situ, which was less than 8 mg kg-1 while the high P level entailed fertilization at the rate of 40 kg P ha-1 application to achieve approximately 35 mg P kg-1 of soil . The root traits measured included angle of adventitious and basal roots, number of basal roots, tap root diameters at 5, 10, 15 and 20 cm soil depths; lateral branching densities at depth 5,10 and 15 cm, nodule score, deep score, shallowness score, 3rd order branching density, and 1.5 branching densities at 5 and 10 cm depth. Plant parameters measured were plant height, number of pods per plant, number of seeds per pod, length of the pods, unshelled weight, shelled weight and number of primary and secondary branches. Photosynthetic parameters measured were photosynthetic rate, intercellular CO2 concentration, water conductance, transpiration rate, vapour pressure deficits, sample cell CO2, sample cell H2O and relative humidity in the cell. All treatment factors were combined as split-split plot arrangement fitted into randomized complete block design; with four replicates. Results indicate that the lateral root branching density at 5 and 10 cm differed significantly (P≤0.05) across cowpea genotypes. Genotype showed significa

Agronomic field trial was planted at two sites, Ukulima and Syferkuil, in Limpopo Province, to determine the response of cowpea to variable rates and methods of zinc application under supplementary irrigation and rainfed conditions, respectively. The experiment was laid out in a split plot arrangement and fitted into a randomized complete block design (RCBD). Treatments consisted of two factors namely zinc rates (0, 5, 10, 15, 20 and 25 kg ha-1) and methods of application (soil and foliar) with white cowpea variety (IT00K-1217) seeds sown. The zinc fertilizer was applied as ZnSO4 (38.5% Zn) while basal phosphorus (30 kg P ha-1) was applied in the form of single super phosphate (10.5% P) so as to eliminate P constraints. Soil application of the zinc fertilizer was band placed near the row of cowpea plant while foliar application was done 3-5 weeks after plant emergence. Growth parameters measured included plant height, number of primary branches, canopy cover, number of trifoliate leaves, days to 50% flowering and pod formation, and fresh biomass as well as yield component attributes. Twenty young cowpea leaves and immature green pods were each harvested at approximately 75% physiological maturity. Crude protein, total nitrogen, potassium, phosphorus, zinc, and iron content and uptake were assessed in the different plant parts. Growth, yield and nutrients data collected were subjected to analysis of variance. Treatments means were separated using Tukey’s test at probability level of 5%, while the response variables were modelled using quadratic polynomial equation. Results obtained revealed that total above ground biomass yield of 6219 kg ha-1 and fresh pod weight of 142.3 g were obtained when zinc was soil applied under rainfed condition compared to 6019 kg ha-1 and 138.0 g for total above ground biomass yield and fresh pod weight, respectively when foliar applied. Soil application gave a total above ground biomass yield of 6298 kg ha-1 and pod fresh weight of 150.9

Winery solid waste materials namely, wine filter materials (FM), grape marc (berry stalks, skins and seeds) and chopped grapevine pruning canes were composted in heaps through a thermophilic process. The filter materials were mixed with the grape marc and grapevine prunings at five rates (10%, 25%, 50%, 75% and 100%) to produce five composts herein designated as C10FM, C25FM, C50FM, C75FM and C100FM, respectively. A laboratory incubation study was thereafter carried out to determine the nutrient release potential of the composts using two soil types with varying textural characteristics. Each compost was mixed with soil at a rate equivalent to 200 kg N ha-1 and the mineral N, available P and exchangeable K content determined over 42 days incubation period. Results revealed that the composts possess high C content and low C:N ratios; and released significantly higher NH4-N and K concentration relative to un-amended control. The differences in the amount of P mineralised among the five compost treatments were not significant while significantly higher amount of K was mineralised at higher FM mix rates. The composts were applied to maize cv. SNK2147 on sandy soil in a greenhouse pot study at five rates (5, 10, 20, 40 and 80 t ha-1) to determine their effects on crop growth and yield as well as on selected soil chemical properties. An un-fertilised control and NPK fertiliser treatments were included for comparison. The pots were arranged in a completely randomized design, with each treatment replicated four times. The C50FM, C75FM and C100FM treatments applied at 80 t ha-1 gave significantly higher maize dry matter yield than the NPK fertiliser treatment. Quantitative estimates of the optimum compost rate for dry matter production ranged from 450 to 1842 g pot-1. Application of these composts significantly increased dry matter yield, plant height, stem diameter and the number of functional leaves per plant compared to the un-fertilised control. The K content of shoot fr

Phospho-composts of different mix ratios (5:5, 7:3, 8:2 and 9:1) were produced through thermophilic co-composting of poultry manure (PM) and sewage sludge (SS) with ground phosphate rock (GPR). Composted PM and SS without GPR addition were included as control. Cured phospho-composts were chemically characterised and used for both laboratory incubation and greenhouse studies, respectively for phosphorus (P) mineralisation and bioavailability, over a period of 42 days. Results revealed that Bray-P1 concentration measured in compost amended soils at 14, 21 and 42 DAI differed significantly (P<0.05) and ranged between 5.47 and 11.14 mg kg-1 and between 5.28 and 11.78 mg kg-1 in poultry manure and sewage sludge-based phospho-composts, respectively. The maximum amount of cumulative P mineralised of 16.06 and 9.98 mg kg -1, respectively in PM and SS-based phospho-composts were obtained from the 8:2 mix ratio. The content of the acid detergent fibre of the different phospho-composts showed positive and significant correlation with cellulose, lignin and total organic carbon (TOC). Similarly, cellulose as well as C:P ratio showed significant correlation with both lignin and TOC. The polynomial relationship between cumulative P mineralised and the various GRP and manure mix ratios revealed significant and positive R2- values of 0.731 and 0.613 for PM and SS-based phospho-composts, respectively. The maximum amount of maize tissue P uptake of 0.12 and 0.11 mg pot-1 in PM and SS-based phospho-compost respectively were also obtained from the 8:2 mix ratio while the least amount of 0.04 mg P pot-1 was obtained from GPR and unamended pots. Maize tissue P uptake following the phospho-compost application was significantly affected by the differences in soil type. Tissue P uptake was 0.06 and 0.11 mg P/pot, respectively in low potential and high potential soils with a significantly higher value. The use of the different phospho-composts showed great potential for amelioration of P-defi

Soybean (Glycine max (L.) Merrill) is considered to be an important grain legume and an oil crop. It is also important in livestock feeding and improvement of soil fertility through biological nitrogen fixation (BNF). Until recently, soybean was not widely grown by smallholder (SH) farmers in Africa. This has led to breeding of promiscuous varieties to ensure wide adoption of the crop by SH farmers, without the use of inoculants or expensive nitrogen fertilizers. Field and glasshouse experiments were conducted during 2012/2013 growing season. One commercial (specific) variety Dundee and three naturally-nodulating (promiscuous) soybean varieties (TGx-1937-1F, TGx-1740-2F, TGx-1835-10E) were evaluated in a field trial for their growth, nodulation and yield response to B. japonicum strain WB74 inoculation. Seed inoculation in the field enhanced chlorophyll content, number of nodules, nodule dry weight, and the percentage of active nodules, number of pods, hundred seed weight, shelling percentage and grain yield. Varietal differences exerted significant (P≤0.05) effect on all field parameters evaluated except on nodule number and percentage of active nodules. TGx-1937-1F achieved the highest number of nodules (28 per plant) while the highest percentage of active nodules (69%) was achieved by TGx-1740-2F. Huge effect of inoculation was observed on Dundee variety, and resulted in significant grain yield increases (237.8%) while smaller gain increases were observed in TGx-1740-2F (43.9%) and TGx-1835-10E (38.7%). The yield of TGx-1937-1F did not respond to inoculation. Two promiscuous (TGx-1937-1F and TGx-1740-2F) varieties and one commercial (Dundee) variety were evaluated in a glasshouse trial for their growth and nodulation response to inoculation in different soil types (sandy clay loam, sandy loam, loamy sand) of Limpopo Province. In the glasshouse inoculation showed effect on chlorophyll content only, and effect of soybean variety was found to be significant on days, Department of Agriculture Forestry and Fisheries

Information on the performance of the maize and pigeonpea intercropping system under dryland conditions of South Africa is scanty. The aim of this study was to determine the optimum P level and productivity of pigeonpea and maize under the dryland intercropping system. Five P rates (0, 15, 30, 45, and 60 kg P ha-1) were applied to both sole and pigeonpea intercropped with maize in a randomized complete block design with 4 replicates. Growth parameters and yield and yield attributes of pigeonpea and maize were measured to determine performance of both crops. There were significant differences in grain yield of pigeonpea as influenced by P rates in both seasons. Highest grain yields of 781 kg ha-1 during 2009/10 and 894 kg ha-1 during 2010/11 were obtained at P rate of 45 kg ha-1. Cropping system significantly influenced grain yield of pigeonpea in 2010/11 season with 37.1% higher pigeonpea grain yield from intercropped plots than in sole pigeonpea plots. There was 21.8% increase in grain yield of pigeonpea across two seasons as influenced by P rate. Maize grain yield showed little response to P rate only during the first season. However, highest maize grain yield of 1699 kg ha-1 was obtained at 60 kg P ha-1 during the 2009/10 season. Maize grain yield was only significantly influenced by cropping system during the 2010/11 season where sole plots achieved higher grain yield of 4148 kg ha-1 compared to 3297 kg ha-1 from intercrop plots. The results revealed that P application increased grain yield of pigeonpea significantly, especially in intercropped plots. The calculated total land equivalent ratio (LER) for the two crops gave positive and higher than one values, which suggests a favourable grain yield advantage for maize/pigeon pea intercrop.

The study was conducted to assess the impact of mining activities on selected soil physical, chemical and microbial properties on farmlands around three selected mining sites. Nine soil samples were collected from each of the following farms : Hans Merensky, Mogoboya and Leon Tom, Foskor Mine and JCI mining sites, respectively. Additional nine soil samples were collected from non-polluted Waterbok farm that serves as a control for the purpose of comparison. The samples were taken at 0–15, 15–30, 30–45 cm depths at three sampling points on each farm for physical, chemical and biological studies. However, soil samples collected for microbial (fungi, bacteria and actinomycetes) counts were surface (0–15 cm) soil samples. Soil chemical properties determined include pHw, electrical conductivity (ECe), exchangeable acidity (EA), organic carbon, available phosphorous, exchangeable cations as well as heavy metal (i.e. Mn, Zn, Cu, Pb, Cd, As and Sb) concentrations. The physical parameters determined include texture (sand, silt and clay) as well as bulk density. Soil pHw and ECe values decreased with depth; and ranged from 6.94 to 6.50 and from 12.24 to 10.76 mS cm-1, respectively. Exchangeable acidity showed a gradual increase with depth and ranged from 0.72 to 0.80 cmol(+)(kg), while percent organic carbon decreased with depth ranging from 1.41 to 2.19 %. Exchangeable cations, particularly K and Mg increased with depth while Ca decreased marginally with soil depth. Available phosphorous content decreased following increases in distance from the pollution source while heavy met.al contamination decreased with soil depth but increased further away from the pollution source. Significantly high loads of Pb, As and Sb were recorded at all depths on the three farms around the mining sites, which were largely responsible for the pollution but worse on the Leon Tom farm; with Pb constituting the greatest pollutant. The concentration of extractable heavy metals in the studied areas, National Research Foundation (NRF)

The soaring prices of inorganic fertilisers among other reasons has persuaded companies to commence producing biological enhanced substances herein refers as industrially manufactured biological amendments (IMBAs) with claims that they could increase crop growth and yield, and also revitalize the soil. Such claims are often without substantial empirical agronomic data to proof the efficacy of these IMBAs. A glasshouse pot trial was conducted during 2008/09 season to assess the effects of graded rates of nine IMBAs (Biozone, Gliogrow, Gromor, Promis, Growmax, Crop care, K-humate, Lanbac and Montys) on maize seedlings establishment and growth over six-weeks. These were assessed at 50, 75 and 100% of the recommended rates together with optimum inorganic NPK fertiliser and a control as check. The IMBAs exerted in many instances a deleterious effect on percent maize seedling emergences when applied at 100% rate. Application rates of 50 and 75% appeared sufficient amongst most IMBAs for encouraging better growth and phenological development of maize, although the most appropriate rate is dependent on the IMBA type. Rainfed trials were conducted for three seasons (2006/07-2008/09) at four localities (Bethlehem, Bothaville, Ottosdal and Potchefstroom) to assess the effects of the same nine IMBAs used above on maize performance and on soil health in a randomised completely block design. The IMBAs were applied based on product manufactures and/or supplier recommendations along with optimum inorganic NPK rate and the unamended control as check. All trial sites were planted to one maize cultivar PAN 6479. Every season, observations on phenological growth traits, grain yield and yield components, nitrogen and phosphorus content, uptake, and agronomic use efficiency, soil chemical and microbial properties and on grain quality traits were measured. The manure-based IMBAs like Gromor, Promis and Growmax generally raised pH (H2O) to between 6.0 and 7.0 which was not always the case