Kraal Manure Research Articles

Earthworms enhance the performance of organic amendments in improving rice growth and nutrition in poor ferralsols

In the Highlands of Madagascar, providing organic amendments (OAs) is the main farmer fertilization practice in upland rainfed agrosystems dominated by nutrient-depleted Ferralsols. Therefore, enhancing the performance of OAs on plant functions is particularly important for improving both plant productivity and agrosystem sustainability. Earthworms are well-known ecosystem engineers involved in the decomposition of organic matter and play a critical role in nutrient turnover. Inoculating earthworms could be a promising approach to improve the fertilizer performance of OAs. However, there is limited knowledge regarding the interaction between earthworms and OAs of varying biochemical qualities on plant growth and nutrition. In this microcosm experiment, we assessed the effect of different types of OAs (i.e., unamended control, conventional farmyard manure, kraal manure, improved farmyard manure, compost, vermicompost, urban waste, taroka, poultry droppings, pig manure) and earthworm inoculation (with and without earthworms) on the growth and nutrition of rice. The endogeic species Pontoscolex corethrurus (Rhinodrilidae) was used in the experiment. After eight weeks of growth, the poultry droppings had the best fertilizer performance, followed by improved farmyard manure and pig manure in treatments without earthworms. The main driver of fertilizer performance appeared to be the quality of OAs. However, other mechanisms, such as an increase in soil pH, may also play a significant role. The inoculation of earthworms significantly enhanced the fertilizer performance of OAs but the magnitude of this enhancement depends on the OAs. Overall, OAs with low fertilizer performance showed a more pronounced response to earthworms. Additionally, earthworms improved the performance of high-quality OAs likely by enhancing the availability of P and Mg. Our findings emphasize the synergistic effects of earthworms and OAs of various qualities on plant growth and nutrition, offering valuable insights for improving fertilization practices in nutrient-poor Ferralsols of Madagascar.

Commercialization of green hydrogen production from kraal manure in the Eastern Cape, South Africa: A review

Renewable Energy Independent Power Producer Procurement launched in 2011 contracts renewable energy producers to supplement the national electricity grid. No preferred bidders produce energy using hydrogen fuel cells, particularly Proton Exchange Membrane Fuel Cell (PEMFC), possibly due to technicalities associated with qualifying hydrogen and fuel cells as renewable. The study explores processes to be followed in South Africa to commercialize green hydrogen production for PEMFC from kraal manure. The paper employed an integrative literature review methodology. There are different stages in product commercialisation, such as developing a product, taking the product to markets, growth, and diffusion. The discussions indicate a huge amount of hydrogen that can be produced from kraal manure that is in abundance in the Eastern Cape. Commercialization of hydrogen production can address global economic goals such as waste management, fighting poverty, reducing unemployment and addressing energy challenges.

Women’s Contribution to Indigenous Knowledge Food Security in the Lokaleng village, North West Province, South Africa

There is an increasing trend of directing food security policies toward empowering women, because, studies have found that indigenous knowledge among women plays a significant role in reducing poverty and food insecurity in their rural households. Although South Africa is considered food secure, many households still suffer from food insecurity. This study intends to investigate women’s contribution to indigenous knowledge of food security. This study employs a qualitative approach and exploratory research design to solve the research objective. Thirty participants took part in the study and data was collected using semi-structured and unstructured interviews. Data analysis was thematic and themes identified were: indigenous knowledge technologies, indigenous food types and contribution to food security. The study found that most women used indigenous technologies, such as animal traction, plough-pull by donkey, kraal manure and cow dung to improve food security. Women also used paraffin, wild onion and “sunlight” bar soap mixture solution to control pests. However, indigenous knowledge of food security might disappear because young people (women) in the community have no interest in indigenous knowledge due to modernisation. Workshops and seminars could be organised to train, empower and educate women on indigenous knowledge and food security. Previous Article

Effects of organic fertilisers on growth, yield and nutritional content of sweet basil (Ocimum basilicum L.)

Sweet basil (Ocimum basilicum L.) is one of the major essential oil-producing species used in culinary and fragrance applications. However, there is a dearth of information pertaining to its organic production in the country. A field study laid out in a Randomized Complete Block Design (RCBD) was conducted at the Horticulture Farm, Luyengo Campus, University of Eswatini to assess the effects of organic fertilisers on the growth, yield and nutritional content of basil. This study consisted of four treatments replicated four times. The organic fertilisers used were chicken manure, kraal (cattle) manure and compost. The rates of application were 40 t/ha for the manures. Chemical fertilizer 2:3:2 (22) + 0.5 Zinc (Zn) and limestone ammonium nitrate (LAN 28%) were included at application rates of 150 kg/ha basal dressing and 100 kg/ha LAN top dressing, respectively. The results showed that the type of organic fertilizer applied affected the growth and yield of sweet basil. A trend in the superiority of the different types of organic fertilisers was observed as chicken manure exhibited higher values of the number of leaves (134.2), branches (78.6), leaf area (30.2 cm2)) and chlorophyll content (68.2 CCI), fresh leaf mass (355 g), and fresh mass of basil plant (691 g). Kraal manure was the second, followed by chemical fertilizer and lastly compost. There were no significant (P > 0.05) differences in P, K, Mn, Cu, and Zn content due to the application of different organic fertilisers. Calcium, Mg and Fe showed significant (p < 0.05) differences among the treatments. The use of chicken manure in the production of basil should be encouraged because its application resulted in relatively higher growth and yields compared to the other fertilisers. Keywords: Organic fertilizers, growth, basil, medicinal properties, mineral content.

The Effects of Organic Fertilizers on the Growth and Yield of Amaranthus (Amaranthus hybridus L.) Grown in a Lath House

Amaranthus is also known as African spinach is a good source of carotene, folic acid, vitamin C, calcium, iron and micronutrients. It is believed to have been used widely among hunter-gatherers. The objective of the experiment was to find the effects of organic fertilizers on amaranthus growth, development and yield. The experimental design was a Randomized Complete Block Design (RCBD) with four treatments and each replicated five times. Plant growth and yield increased (P<0.05) on amaranths fertilized with stillage. Kraal manure followed the stillage in terms of performance with the control (no fertilizer) recording the least significant effect on growth and yield of amaranthus. Because of stillage's impact on the growth and yield of amaranthus, it is recommended for a grower aiming for high yields of amaranthus using organic fertilizer.

Influence of Kraal Manure, Chicken Manure and Inorganic Fertilizer on Growth, Yield and Post-harvest Quality of Pepper (Capsicum annuum L.) in a Sub-tropical Environment

The excessive unjustified use of some kinds of fertilizers has seen some farmers realizing poor quality fruit that does not appeal to the final consumer, thus negatively affecting the effort of alleviating poverty in the Kingdom of Eswatini. This experiment was carried out at the Horticulture Department Lath House, Faculty of Agriculture, Luyengo Campus of the University of Eswatini to determine the growth, yield and shelf-life of green pepper when fertilized with kraal manure, poultry manure and inorganic fertilizer. The experiment was conducted to find the optimum levels of fertilizers that promotes the growth of pepper and to find the effects of different fertilizers on yield and quality of pepper. The treatments included kraal manure applied at 60 t/ha, [NPK (2:3:2) 37] at 370 kg/ha, chicken manure at 40 t per hectare and the control with no amendment. The results showed that growing pepper using the four treatments significantly affected its growth rate, leaf number, fruit number and its (fruit) shelf life. Pepper grown using inorganic fertilizer had the highest leaf number followed in decreasing order by chicken manure, kraal manure and lastly peppers which did not receive any amendment. There were no significant difference in the growth rate of pepper in the inorganic fertilizer and chicken manure treatments. Similarly, there was no significant difference of pepper grown with chicken manure and chemical fertilizer in the number of days it took the harvested pepper to reach 100% decay stored at room temperature for 21 days. Yet pepper grown with kraal manure was significantly different from the two as it showed 20% decay rate in the same number of days. Although the control had the least decay, the yield was the lowest thus it is not recommended. Kraal manure at 60 t/ha is recommended in the production of pepper with a longer shelf life.

Effects of organic and inorganic fertilisers on the growth and yield of amaranth (Amaranthus hybridus)

Amaranth is a traditional leafy vegetable of the genus Amaranthus spp., which has been consumed throughout history. Amaranth has great potential as a sustainable crop that could improve household food security, nutrition security and farm incomes. The growth environment of amaranth, can have a major impact not only on the productivity of the crop but its nutritional value as well. Production of amaranth in developing countries like Swaziland is very low, if any at all. This could be attributed to, among some reasons, lack of agronomic information on production of amaranth. The objective of this study was to determine the effects of different types of fertilisers on the growth and yield of Amaranthus hybridus. The trial was done at Malkerns Research Station, in Swaziland. The treatments were 20 t ha(-1) kraal manure, 40 t ha(-1) kraal manure, 100 kg ha(-1) 2.3.4 (39) + 5% Zn (compound NPK), 150 kg ha(-1) 2.3.4 (39) + 5% Zn and the control (no fertiliser). The experimental design was a randomised complete block design. Data were collected at 4, 5 and 6 weeks after planting. The data were subjected to analysis of variance through SPSS 20. Mean separation test was performed by the Duncan's new multiple range test at P=0.05 significant level. Addition of any type of fertiliser had significant (P 0.05) different from each other in all the growth and yield parameters at the different harvest stages. It was concluded that addition of fertiliser, either organic or inorganic, promotes the growth rate and yield of Amaranthus hybridus.

Effects of sheep kraal manure on growth, dry matter yield and leaf nutrient composition of a local <i>Amaranthus</i> accession in the central region of the Eastern Cape Province, South Africa

Indigenous vegetables that supply abundant amounts of protein, vitamins, calories and minerals could alleviate problems of malnutrition, in developing countries. Amaranthus is one such vegetable that could be domesticated and cultivated but information on its fertility requirements is scanty. A dry-land field experiment was therefore conducted to study the effects of sheep kraal manure application rates on growth, fresh and dry matter yields, nutrient uptake and grain yield of one of the Amaranthus accessions that grow in the wild in the Eastern Cape. The treatments were sheep kraal manure rates ranging from 0 to 10 t/ha and an NPK {2:3:4(30) + 0.5% Zn} fertiliser as a positive control at 150 kg/ha. Low manure rates (≤2.5 t/ha) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilised control, whereas higher rates (5 and 10 t/ha) and NPK fertiliser gave greater plant heights and higher yields at both 30 and 60 days after transplant (DAT) (p<0.05). At 30 DAT, manure application rates of ≥2.5 t/ha and the NPK fertiliser treatment, produced greater shoot dry-matter yields (≥29.35 g/plant) than the unfertilised control (17.11 g/plant). Uptake of N and P in the leaves increased with increase in manure application rate with N uptake reaching a maximum of 308 mg N /plant at a manure rate of 2.5 t/ha which corresponded with the maximum dry matter yield of 45.97 g/plant. There was no effect of manure rate or fertiliser on residual soil N and Ca, whereas P, K, Mg and Zn were increased (p<0.005). The findings suggested that ≥2.5 t/ha sheep kraal manure could result in growth, nutrient uptake and yield comparable to 150 kg/ha NPK fertiliser for the Amaranthus accession used in this work.Keywords: Amaranthus accession, sheep manure, dry matter yield, nutrient composition, residual nutrients

Comparative effects of jatropha seedcake, chicken and kraal manures on selected soil properties, growth and yield of tomato (Lycopersicon esculentum)

A field trial was conducted to evaluate the comparative effects of jatropha seedcake, chicken and kraal manures on selected soil properties, growth and yield of tomato in Zambia during the cropping season of 2012-13. A Randomized Complete Block Design (RCBD) with four replicates and six treatments, namely- jatropha seedcake (5.0 t ha-1), chicken manure (5.0 t ha-1), kraal manure (5.0 t ha-1), jatropha seedcake (2.5 t ha-1) + chicken manure (2.5 t ha-1), jatropha seedcake (2.5 t ha-1) + kraal manure (2.5 t ha-1) and control (0.0 t ha-1) was used. Soil total N, P, K, Ca, Mg, SOM, soil pH, bulk density, plant height, number of branches, number of fruits plant-1, and mean fruit weight effects were subsequently monitored. Organic manures significantly increased total N, available P, exchangeable K, Ca, Mg, SOM, soil pH, plant height, number of branches, number of fruits, mean fruit weight and yield of tomato compared to the control. Organic manures also significantly reduced soil bulk density compared to the control. Among the organic amendments treated alone, jatropha seedcake gave the highest yield of 28.62 t ha-1 compared to chicken manure (28.20 t ha-1) and kraal manure (27.50 t ha-1). Maximum yield benefits came from a mixture of jatropha seedcake + chicken manure (29.60 t ha-1)and jatropha seedcake + kraal manure (29.00 t ha- 1) which could have been due to balanced proportions of major nutrients required for tomato growth. Jatropha seedcake mostly performed favourably the same or better than chicken and kraal manures in many aspects.Int. J. Agril. Res. Innov. & Tech. 8 (1): 1-6, June, 2018

Stability and Maturity of Different Poultry Manures and Potential Utilization for Horticultural Production

This study evaluated stability, maturity and the efficacy of different poultry litter for possible use in container plant production. Three types of poultry manure- Battery cage (BC), Deep litter (DL) and Free range (FR) were used, with Kraal manure (KM) as a comparison. The experiment was set up as a Split- split design with 6 replications. Composting period was main plot, poultry manure type the split plot and mixing ratio as the split- split plot. The litter was mixed with garden soil in 2 ratios (3:1 and 1:1 soil: manure ratio) and tested for up to 12 weeks. Rape (Brassica napus) was used as a bioassay for maturity, which was determined at 1 month, 2 months and 3 months. The pH declined slightly from 7 to about 6 for all treatments except for the kraal manure. Respiration trends were similar to electrical conductivity. Within 2 weeks of curing the respiration rate for all manures declined to below 4 mg CO2- C/ kg. At the end of 12 weeks curing Battery cage had highest total nitrogen (2.32 %), followed by Free range (1.25 %), Deep litter (0.73 %) and Kraal manure was lowest at 0.35 %). Maturity (rape survival) increased with compositing time. After 3 months of curing Kraal manure had highest survivability of rape. The DL at 1:1 ratio had the lowest survival of 67%. At 12 weeks except for BC at 3:1 all treatments had 100 % survival. The results showed that nitrogen rich manures (DL and BC) needed longer curing in order for them to reach maturity.

Perceptions of Climate Change and the Potential for Adaptation in a Rural Community in Limpopo Province, South Africa

Perceptions of climate change by rural communities are centered on observations of variations in temperature and rainfall patterns supported by observations and projections on climate alterations in the form of increased temperatures and scarce rainfall by scientists worldwide. The present study documented perceptions of climate variation and the community’s ability to adapt to climate change hazards threatening the production of subsistence crops. Data were collected through interactions with 100 participants. In the study, climate change is explained as variations in temperature and rainfall patterns which resulted in excessive heat, erratic rainfall patterns and drought negatively impacting on subsistence crop production. Community members have the potential to limit the impacts of climate hazards on subsistence crop production. The negative impacts of climate hazards are limited by community members’ indigenous knowledge of rainfall prediction, the seasons, crop diversification and mixed cropping. Mulching and the application of kraal manure improve the soil structure and fertility to reduce crop failure. These adaptation measures are resilient to the negative impact of climate hazards and may be helpful in the development of adaptation policies to assist rural communities vulnerable to climate change hazards.

Effects of Liquid Manure on Growth and Yield of Spinach (<em>Beta vulgaris</em> Var Cicla) in a Sub-tropical Environment in Swaziland

A study was conducted to determine the effects of liquid manure on growth, development and yield of spinach. A randomized complete block design experiment was conducted in pots, in a 50% semi shaded lath house. The four treatments were solid kraal manure applied at 40 t/ha; liquid manure applied at 40 m3/ha; liquid manures solid remains applied at 40 t/ha and control of inorganic chemical fertilizer applied at 150 kg/ha. There were four replications per treatment. The growth parameters that were measured included the average number of leaf development per week, leaf height, leaf width, leaf area, leaf area index and the fresh biomass. For the growth parameters measured the results showed that the highest values were obtained in spinach plants fertilized with inorganic fertilizer followed in decreasing order by those fertilized with solid kraal manure, liquid manure solid remains and lastly liquid manure. The spinach fresh biomass mean yield for the treatment of inorganic chemical fertilizers was the highest at 54.4 g per plant. The lowest spinach yield of 17.9 g per plant was obtained from liquid manure treatment. The spinach yield from inorganic fertilized plants was significantly (p≤0.05) different from that of liquid manure and liquid manure solid remains. However, the yield from solid kraal manure treatment and inorganic chemical fertilizers was not significantly different, implying that kraal manure could be used to produce a high yield of the vegetable at a lower cost compared to inorganic fertilizer. Therefore it is recommended that farmers should continue to use solid kraal manure since the yields produced were similar to that of chemical fertilizers.

English

African indigenous leafy vegetables have the important role of providing essential minerals, vitamins and amino acids in diets of poor smallholder farmer households in sub-Saharan Africa. A study was conducted to quantify the influence of applying cattle and goat manure on the biomass yields and crude protein content of two commonly used African leafy vegetables (Cleome gynandra and Amaranthus hybridus) when subjected to varying leaf cutting management. Treatments for each vegetable consisted of a combination of three manures (control, cattle and goat) and three cutting regimes (cutting edible leaves, all harvestable leaves and cut only at the end) utilised in randomised block design. The results showed significant increase in leaf biomass yields and crude protein content of both vegetables due to manure application. Goat manure was superior to cattle manure due to its higher quality in terms of nutrient content and lower C:N ratio. Cutting the edible leaves more frequently, every fortnight, was associated with the highest leaf biomass yield and crude protein in treatments where manure was applied. It was concluded that potential exist for smallholder farmers to benefit from adopting appropriate manure and leaf cutting regime. A combination of goat manure and frequent cutting of the tender edible leaf tips is recommended. The results point to the potential of maximizing biomass yield and quality of the vegetable leaves by adopting appropriate nutrient supply and leaf cutting regime.   Key words:       Animal kraal manure, nutritional security, smallholder farmers, indigenous vegetables, leaf defoliation.

Response of carrot (Daucus carota L.) yield and quality to organic fertiliser

A field study was conducted at Umsunduze Training Centre, KwaZulu-Natal, for two seasons (2005 and 2006) to determine the response of carrot (Daucus carota cv. Kuroda) to organic fertiliser. Three different organic fertilisers were applied at four rates (chicken manure: 0, 6.25, 12.5 and 25 kg 10 m−2; kraal manure: 0, 12.5, 25 and 50 kg 10 m−2; and compost: 0, 25, 50 and 100 kg 10 m−2). The experiment was laid out as a complete randomised block design with four replications. Leaf number and length, root fresh and dry mass, root length, shoulder diameter, root total soluble solids (TSS) and grade were recorded. Chicken manure-treated plants produced more leaves than compost (2005) and longer leaves than kraal manure (2006) treated plants. The TSS of roots treated with chicken manure or compost was lower than that of roots not receiving fertiliser (2005). Poorer quality roots were harvested from compost than chicken or kraal manure-treated plants. As organic fertiliser rate increased, leaf number, length, root fresh mass and shoulder diameter increased. Root TSS and dry mass decreased as organic fertiliser rate increased and roots were of a lower grade. Organic fertiliser can be beneficial to carrot yield and quality within specific application levels.

Response of grain amaranth (Amaranthus cruentus L.), to method and rate of cattle kraal manure application at Kadawa and Samaru in Nigeria

Field experiments were conducted between June and October 2010 wet season at two different locations. The first was at the Horticultural Research Garden of the Institute for Agricultural Research (IAR), Samaru in the Northern Guinea Savanna agro-ecological zone and the second experiment was conducted at the Research Farm of the Irrigation Research Sub-Station (IRS), Kadawa in the Sudan Savanna agro-ecological zone also of the Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria to evaluate the response of grain amaranth growth and green edible vegetable yield components to three methods of cattle kraal manure application (broadcasting, side banding and spot placement incorporated) and five rates of cattle kraal manure application (0, 5, 10, 15 and 20 t ha-1), using the variety ?Pure branch?. The experiment was laid out in a randomized complete block design (RCBD) and replicated three times. Cattle kraal manure application rates significantly (p > 0.05) increased growth of green edible vegetable yield characters of grain amaranth except stem girth at Samaru. Growth and green edible vegetable yield characters were generally not influenced by methods of cattle kraal manure application except for plant height, number of leaves per plant at 12 WAT at Samaru, and plant fresh weight at 12 WAT at Kadawa and dry weight at 4 and 12 WAT at Samaru and 12 WAT at Kadawa. Application of cattle kraal manure of 10 t ha-1 to Amaranthus cruenthus gave the highest mean values which were comparable to those of 15 and 20 t ha-1 rates for all the characters measured such as plant height, number of leaves, leaf area, fresh and dry weights. Thus, the finding suggests that 10 t ha-1 should be recommended to farmers growing Amaranthus in the Northern Guinea and Sudan Savanna of Nigerian agro-ecologies.

Analysis of persistence soil nutrient status in abandoned cattle kraals in a semi arid area in Botswana

The aim of this study was to analyze the depletion of soil nutrients with time on abandoned kraals in a peri-urban area of Botswana. Active kraals are enriched with nutrients through the accumulation of animal droppings and this study was aimed at assessing how long the impact of this soil nutrient enrichment persists after kraal abandonment. A total of 25 disused kraals, that had been abandoned for periods ranging from 1 to 45 years were sampled. The soil parameters analyzed included particle size distribution (%), bulk density (g/cm3), pore space (%), moisture content (%), pH in water and KCl solution, EC (µS/cm), organic matter (%), CEC (meq/100g), exchangeable Ca++(cmolc/kg), Mg++(cmolc/kg), K+(cmolc/kg), Na+ (cmolc/kg), nitrogen [NH4-N (mg/kg), NO3-N (mg/kg), TKN (%), and Olsen P (mg/kg). Results showed that soil nutrient concentrations on abandoned kraals generally were significantly higher than at the control sites. Soil nutrient concentrations decreased with time as abandoned kraals retrogressed towards their pre-kraal conditions. However, the effects of soil nutrient enrichment from animal wastes persist long after kraal abandonment. For example, soil Olsen P, Ca++ and Mg++ levels in kraal sites that had been abandoned for over 45 years were still significantly higher than in the control sites. In a pastoral system such as is practiced in Botswana where kraal manure is not used as soil amendment, the whole ecosystem suffers as soil nutrients are transferred and concentrated at isolated spots (kraals). Key words: Abandoned kraal, soil nutrient status, pastoral systems, semi-arid.

Analysis of the effects of kraal manure accumulation on soil nutrient status through time

This study investigated the influence of the accumulation of animal wastes on the soils of active kraal sites through time. This investigation involved the sampling and analysis of the soils of kraals that had been in use for periods ranging from 2 to over 45 years. Soil sampling and analysis were done both in the dry and wet seasons for comparative purposes. The properties of the kraal soils were compared with those of control sites. Samples were taken from 25 kraals categorized into 5 age (length of use) groups: 40 years. The soils were sampled at two depths, 0 ‐ 15 and 15 ‐ 35 cm. Soil parameters analyzed included particle size distribution (%), bulk density (g/cm 3 ), pore space (%), moisture content (%), pH in water and in potassium chloride solution, EC (µS/cm), organic matter (%), CEC (meq/100g), exchangeable bases: Ca ++ (cmolc/kg), Mg ++ (cmolc/kg), K + (cmolc/kg), Na + (cmolc/kg); nitrogen: NH4-N (mg/kg), NO3-N (mg/kg), TKN (%), and Olsen P (mg/kg). Results showed a direct correlation between length of active kraal utilization and impact of animal waste concentration on the soil with correlation coefficients as high as r = 0.99 and r = 0.95 for pH and OM respectively. Nutrient levels in kraal soils of all ages were significantly higher (P = 0.05) than those of the control site soils. Most nutrient elements showed increases ranging from about 2 - 30 times greater than in the control site soils. Soil nutrient levels were higher in the dry season than in the wet season. The nutrient enrichment in the kraals extended deep into the soil, at least, to the 35 cm depth. The organic and nutrient enrichments of the soils also had very positive effects on soil moisture and structural characteristics. However, this highly localized nutrient enrichment of kraal soils is detrimental to the long term sustainability of arid ecosystems and soil productivity. The nutrients concentrated in kraals have been harvested from the surrounding areas by grazing animals and transferred to the kraal sites. In a situation of sedentary kraaling that exists in semi arid lands of Botswana where rotation of kraal sites or the harvesting of animal manure from kraals for use as soil manure is not commonly practiced, the concentration of soil nutrients at scattered kraal spots causes an imbalance in the spatial pattern of soil and plant productivity in the arid land ecosystem. The entire ecosystem is made poorer by this phenomenon.

Effects of sheep kraal manure on growth, dry matter yield and leaf nutrient composition of a local amaranthus accession in the central region of the Eastern Cape Province, South Africa<sup>#</sup>

Indigenous vegetables that supply abundant amounts of protein, vitamins, calories and minerals could alleviate problems of malnutrition, in developing countries. Amaranthus is one such vegetable that could be domesticated and cultivated but information on its fertility requirements is scanty. A dry-land field experiment was therefore conducted to study the effects of sheep kraal manure application rates on growth, fresh and dry matter yields, nutrient uptake and grain yield of one of the Amaranthus accessions that grow in the wild in the Eastern Cape. The treatments were sheep kraal manure rates rangingfrom 0 to 10 t/ha and an NPK {2:3:4(30) + 0.5% Zn} fertiliser as a positive control at 150 kg/ha. Low manure rates (.2.5 t/ha) resulted in plant heights and fresh matter yields which were comparable to those in the unfertilised control, whereas higher rates (5 and 10 t/ha) and NPK fertiliser gave greater plant heights and higher yields at both 30 and 60 days after transplant (DAT) (p

Long-term effects of mineral and organic fertilization on soil organic matter fractions and sorghum yield under Sudano-Sahelian conditions

Abstract. Knowledge of changes in soil organic matter (SOM) fractions resulting from agricultural practice is important for decision-making at farm level because of the contrasting effects of different SOM fractions on soils. A long-term trial sited under Sudano-Sahelian conditions was used to assess the effect of organic and inorganic fertilization on SOM fractions and sorghum performance. Sorghum straw and kraal manure were applied annually at 10 t ha−1, with and without urea at 60 kg N ha−1. The other treatments included fallowing, a control (no fertilization), and inorganic fertilization only (urea, 60 kg N ha−1). Fallowing gave significantly larger soil organic carbon and nitrogen (N) levels than any other treatment. Total soil SOM and N concentrations increased in the following order: urea only < straw < control < straw+urea < manure with or without urea < fallow. Farming had an adverse effect on SOM and N status; however, this mostly affected the fraction of SOM >0.053 mm (particulate organic matter, POM). The POM concentrations in the control, straw and urea-only treatments were about one-half of the POM concentrations in the fallow treatment. POM concentrations increased in the following order: urea only < control < straw with or without urea < manure with or without urea < fallow. The fraction of SOM <0.053 mm (fine organic matter, FOM) was greater than POM in all plots except in fallow and manure+urea plots. Total N concentration followed the same trend as SOM, but cultivation led to a decline in both POM-N and FOM-N. Crop yield was greatest in the manure plots and lowest in the straw, control and urea-only plots. Results indicate that under Sudano-Sahelian conditions, SOM, POM and FOM fractions and crop performance were better maintained using organic materials with a low C/N ratio (manure) than with organic material with a high C/N ratio (straw). Urea improved the effect of straw on crop yield and SOM concentration.

Characterization of Organic Soil Nitrogen in a Hutton Series Soil from the Kwazulu‐Natal Midlands

The labile soil organic nitrogen pool and the effect of old kraal manure on the pools of labile organic N in a Hutton series soil from Cedara in the Midlands of KwaZulu‐Natal in South Africa were determined. Four levels of kraal manure (0, 5, 10, and 15 t ha−1 oven dry basis) were applied in the field in a randomized complete block design with three replicates. Total soil N, microbial biomass N, and anaerobic mineralizable N were determined on soil samples taken a month after manure application. All three pools of soil organic N showed significant (p<0.01) increases due to manure addition. However, microbial biomass only showed significant changes if the difference in the manure rate was >10 t ha−1. Considering the work involved in measuring each pool and the variability among replicates it was apparent that anaerobic mineralizable N was the best pool for monitoring small changes in soil fertility. In addition, approximately 13% of the total soil organic N in the soil studied was potentially available to plants. Between 12% and 15% of the N added in manure was potentially available to plants, indicating that organic N in the well‐decomposed manure was more or less similar to that in the soil. With different manure treatments, there was also a significant correlation between microbial biomass N, and anaerobic mineralizable N although the former was more variable than the latter.