34 research outputs found
Soil Nutrient Status of Smallholder Cassava Farms in Southern Ethiopia
No full textThis study investigates the soil nutrient status of cassava farms in Wolaita, Southern Ethiopia. Soil samples were randomly collected form 12 cassava farms and soil management practices on the farm were also recorded. The samples were analyzed for physical and chemical properties. The result reveled that cassava in the study sites was cultivated under low to no fertilizer application in which farmers applied phosphorous (P) and nitrogen(N) fertilizer ranging from nil to 32.2 kg/ha P2O5 and nil to 19.2 kg/ha, respectively. Non- use of organic fertilizer and complete removal of crop residues from the field were also common farm practices. The physico-chemical properties of cassava farms revealed clay textural class with an ideal bulk density (1.06 to1.35 gcm-3). The soil pH was strong to moderate acidity (pH 5.0–6.1). The farms were very low to low in their organic carbon (1.2–2.5%) and total N content was low (< 0.2%). The soil available P was below the critical level (< 30 mg kg-1) in 100% of the cassava farms, while 92% of the studied soils showed sulfur (S) deficiency (< 20 mg kg-1). Exchangeable calcium (Ca) on 83% of farms was low (< 5 Cmol (+) kg-1), while magnesium (Mg) was under medium category. Potassium (K) to Mg varied from 0.4:1 to 0.9:1. Thus, Mg induced K deficiency was speculated on 75% of cassava farms. The result regarding micronutrient status indicated that boron (B) and copper (Cu) in 100% of the cassava farms were deficient. Lower content of iron (Fe) on 33% and zinc (Zn) on 17% farms was also recorded. All soil samples were adequate in manganese. Regardless of their share, about 57% essential elements derived from soil (N, P, K, S, B, Cu, Fe and Zn) were found limiting nutrients to cassava production in the study area. Thus, correcting the limitation through balanced fertilizer application is needed. Further study is suggested in order to have firm conclusion. Keywords: Cassava, Ethiopia, Nutrient, Soil, Wolait
Explaining Soil Fertility Heterogeneity in Smallholder Farms of Southern Ethiopia
No full textSoil is spatially heterogeneous and needs site-specific management. However, soil nutrient information at larger scale in most cases is lacking. Consequently, fertilizer advisory services become dependent upon blanket recommendation approach. Subsequently, it affects yield and profitability. This study is aimed at explaining soil fertility heterogeneity in Wolaita zone, Southern Ethiopia. About 789 soil samples were collected to evaluate soil physical (color, particle size, and bulk density) and chemical properties (pH, OC, N, P, K, Ca, Mg, B, Cu, Fe, Mn, Zn, PBS, and CEC). The laser diffraction method for soil particles and mid-infrared diffused reflectance (MIR) spectral analysis for OC, TN, and CEC determination were employed. Mehlich-III extraction and inductively coupled plasma (ICP) spectrometer measurement were used for the remaining elements. The result based on principal component analysis showed that 52% of the total variations were explained by exchangeable bases, CEC, pH, available P, Cu, B, and particle sizes. Clay texture and acidic soil reaction are dominant. Soil parameters with the following ranges were found at low status: soil OC (0.2–6.9%), total N (0.01–0.7%), available P (0.1–238 mg/kg), S (4–30 mg/kg), B (0.01–6.9 mg/kg), and Cu (0.01–5.0 mg/kg). Besides, low levels of exchangeable Ca, Mg, and K (Mg-induced K deficiency) on 22, 34, and 54% soil samples, respectively, were recorded. The soil contained sufficient Fe, Zn, and Mn. In conclusion, the study aids in developing practical decision for optimum soil management interventions and overcomes lower productivity occurring due to fertilizer use that is not tailored to the local conditions. Overall, continuous cropping, low return of crop residues, and low and/or no fertilizer application might have caused the low status of N, P, K, S, B, and Cu. Therefore, application of inorganic fertilizers specific to the site, lime in acidic soils, and organic fertilizers are recommended to restore the soil fertility and improve crop productivity
Response of Potato (Solanum tuberosum L.) to NPS Fertilizer Rates and Inter-Row Spacing in Kechi District, South Western Ethiopia
No full textFertilizer requirement and spacing vary across locations due to differences in soil types, nutrient and moisture availability, economic factors, and other environmental conditions. Therefore, a field experiment was carried out to investigate the effect of different rates of NPS fertilizers and inter-row spacing on growth, yield, yield components, and economic performance of potato in Kechi research farm, Dawro zone of south-western Ethiopia. The experiment was arranged in factorial combination of six NPS (19N–38P2O5–7S) fertilizer rates (0 kg/ha, 50 kg/ha, 100 kg/ha, 150 kg/ha, 200 kg/ha, and 250 kg/ha) and five inter-row spacings (45, 55, 65, 75, and 85 cm) which were laid out in RCBD with three replications using the Gudene variety. Growth, yield component, and yield data were collected and analyzed. In addition, a partial budget analysis was performed. The results showed that the main effect of NPS fertilizer and inter-row spacing had significantly (P<0.05) affected plant height, tuber number, tuber yield, and tuber size and average tuber weight. Maximum marketable tuber number per plant (11.627), total tuber number per plant (13.020), average tuber weight per plant (83.493 g), the proportion of large-sized tuber number per plant (41.893%), marketable tuber yield (48.056 t/ha), and total tuber yield (51.145 t/ha) were obtained from 200 kg/ha of NPS fertilizer which was statistically at par with 150 kg/ha and 250 kg/ha NPS, while the lowest result for those parameters was recorded from unfertilized plots. Results regarding inter-row spacing revealed that the highest marketable tuber number per plant (11.744), total tuber number per plant (13.144), and average tuber weight per plant (85.559 g) were recorded at 75 cm, while the lowest result for these parameters was recorded at 45 cm. Moreover, the highest marketable tuber yield (45.084 t/ha) and total tuber yield (48.462 t/ha) were obtained from the inter-row spacing of 65 cm which was statistically at par with 55 cm inter-row spacing, while the lowest result for these parameters was recorded at 85 cm. The partial budget analysis further revealed that 200 kg/ha NPS fertilizer gave the maximum net benefit. However, 150 kg/ha NPS resulted in the highest marginal rate of return (4303.91%). Thus, 150 kg/ha NPS fertilizer and inter-row spacing of 55 cm or 65 cm are suggested for attaining higher potato yield
Decomposition Dynamics of Leaf Litter Mixtures Enriched with NPS Fertilizer and Resultant Effects on Common Bean Productivity in Nutrient Depleted Soil
No full textOrganic materials have a nonreplaceable role to improve soil quality and productivity. Yet, processes related to decomposition and nutrient supply capacity are restricted under nutrient-depleted soils. Thus, a field experiment was conducted to evaluate the decomposition rate of leaf litter mixtures treated with mineral nitrogen (N), phosphorous (P), and sulfur (S) fertilizer in the form of NPS (19N38P2O57S), and their effects on agronomic performance of common bean (Phaseolus vulgaris L.). The mixtures of croton (Croton macrostachyus) and erythrina (Erythrina brucei) leaf litters (LLs) were placed at 20 cm depth in a litterbag at a rate equivalent to 2.5 and 5 t/ha, and treated with four NPS rates (0, 50, 100, and 150 kg/ha). The leaf litters have low carbon (C) to N ratio. The experiments (litterbag and crop response) were laid out in a randomized complete block design with three replications. The decomposition pattern was monitored at a two week interval (15, 30, 45, and 56 days after application) and assessed for daily decomposition rate (k), weight loss, and time required to decompose half of the residue (t50). For the crop response experiment, selected growth and yield component parameters, and grain yield data were recorded. The results indicated that NPS fertilizer and the amount of LL were significantly (p 0.98). Half-lifetime was significantly (p<0.001) decreased with the increasing rate of NPS application (r = −0.86). The t50 values, averaged over 56 days, were between 38.9 days (nontreated LL) and 27.8 days (150 kg NPS/ha), respectively. The result regarding agronomic performance indicated that the application of NPS fertilizer on the leaf litters significantly (p<0.01) increased the growth, yield component, and grain yield of common bean. For instance, 150 kg NPS/ha on 2.5 t/ha LL has resulted in a 79% grain yield advantage over LL without NPS. Grain yield also showed significant relationship (p<0.01) with k (r = 0.67), mass loss (r = −0.67), and t50 (r = −0.66). The finding suggests that for plant residues with a narrow C/N ratio in nutrient-depleted soils, the addition of mineral NPS fertilizer is advantageous for increased decomposition and yield of legume crops
Response of Maize (Zea mays L.) to Integrated Fertilizer Application in Wolaita, South Ethiopia
No full textAn on farm participatory experiment was conducted during rainy seasons of 2009 and 2010 at two locations to introduce the culture of integrated fertilizer management on maize. No fertilizer, blanket dose of inorganic fertilizer (100kg Urea/ha and 100kg DAP/ha), 5ton compost ha-1 alone, (5ton compost ha-1 + 25kg urea ha-1+ 100 DAP/ha), (5ton compost ha-1 + 50kg urea ha-1 + 100 DAP/ha), (5 ton compost ha-1 + 75kg urea ha-1+ 100 DAP/ha) were evaluated. The experiment was laid out in randomized complete block design with four replications. Soil analysis before sowing indicated that the major nutrients (N, P) were found at low levels, where as the compost analysis indicated as it contained considerable amounts of nutrients. The result indicated that integrated fertilizer application revealed a significant influence (P<0.001) on growth, yield components and grain yield of maize. During 2009, the maximum grain yield (6.95 and 6.53 ton ha-1) at Dendo Ofa and Chifisa were obtained from compost with 75 and 50 kg ha-1 urea, respectively; which 54.39% higher over the control (3.17 ton ha-1) at Dendo Ofa; and 52.83% more than the control (3.08 ton ha-1) at Chifisa. During 2010, the maximum grain yield (6.05 ton ha-1) which was 50.74% more than sole compost (2.98 ton ha-1) was recorded at Dendo Ofa from compost with 75 kg ha-1 urea; whereas, in Chifisa inorganic fertilizer gave maximum grain yield (6.79 ton ha-1) which was 49.04% higher than the sole compost (3.46 ton ha-1). However, statistically similar performances between integrated and inorganic fertilizer applications have been recorded. In the mean while, sole compost and unfertilized plots showed least performance on growth, yield component and grain yield of maize. In general, combined use of compost with inorganic fertilizer at (5 ton/ha + 50kg urea/ha + 100kg DAP/ha) has been suggested than using inorganic fertilizer alone to obtain better growth and yield of maize; and improving physico-chemical properties of the soil on sustainable basis. Keywords: Compost, Inorganic fertilizer, Integrated Nutrient Management and Maiz
Mapping the essential soil nutrients status of smallholder farmers fields in the Wolaita area, southern Ethiopia
No full textSoil properties can vary significantly within farmland or across landscapes due to a combination of physical, chemical, and biological processes. It is essential to understand this spatial variation to effectively manage soil nutrients and enhance crop yield sustainably. Thus, the purpose of this study was to investigate the spatial variability of essential plant nutrients in agricultural lands in Wolaita Zone, southern Ethiopia. A total of 789 soil samples were collected and analysed for macro- and micronutrients. Soil samples were analysed to determine the content of macronutrients [total nitrogen (TN), available phosphorous (P), sulphur (S), and calcium (Ca)] and micronutrients [boron (B), copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn)]. The measured data were first subjected to descriptive statistics, and the digital soil map (DSM) that shows spatial variability was generated after geostatistical analysis. The result showed that there was low [S, Mn], moderate [TN], and high [P] variability in the nutrient concentrations among fields. The nutrient concentration varied between 0.02-0.47% (TN), 0.78-26.22 mg kg-1 (P), 6.45-17.50 mg kg-1 (S), 0.05-1.83 mg kg-1 (B), and 0.05-2.64 mg kg-1 (Cu). The contents of TN, P, S, B, and Cu were low. The DSM further exhibited the wide-ranging spatial variability structures in which, from the total area, 64.8% (TN), 100% (P), 100% (S), and 98% (both B and Cu) have indicated low status. In addition, Mg-induced K deficiency on 68% of studied area was suspected. Based on these findings, it is recommended that site-specific nutrient management practices be implemented on smallholder farms, and the nutrient requirements of major crops should be calibrated accordingly
Effects of Organic Nutrient Sources and NPS Fertilizer on the Agronomic and Economic Performance of Haricot Bean (Phaseolus vulgaris L.) in Southern Ethiopia
No full textDespite the fact that mineral fertilizers are widely considered as a major option for addressing the crisis of nutrient depletion, their use among smallholder farmers is not adequate due to an escalating cost. Alternatively, nutrient-rich organic sources that are easily available to farmers are not widely promoted. Thus, this study was carried out in the research field of Wolaita Sodo University, Southern Ethiopia, to evaluate the effects of locally available organic nutrient sources and nitrogen (N) phosphorus (P) sulfur (S) fertilizer (19N-46P2O5-7S) on the productivity and economic performance of common bean. The organic materials used were Croton (Croton macrostachyus) and Erythrina (Erythrina brucei) at 2 : 1 ratio, respectively. The experiment was laid out in a randomized complete block design with three replications. Treatments for organic fertilizer (OF) were 0, 2.5, and 5 t·ha−1 and for NPS fertilizer were 0, 50, 100, and 150 kg·ha−1. Chemical composition analysis of organic materials showed high nutrient content where the amount varied from 4.7%–5.2% N, 11.07–18.6 mg/kg P, and 2.12%–3.07% K. Results on agronomic parameters revealed that the leaf area index, grain weight, number of pods per plant, dry matter per plant, and grain yield of haricot bean were significantly affected by both main and combined effects of NPS and OF fertilizers. The grain yield under integrated application of 150 kg NPS/ha and 2.5 t·OF/ha (4.16 t/ha) was significantly higher than that obtained from unfertilized crop (1.01 t/ha) by 312%. Additionally, it resulted in 34%, 31%, and 79% yield increment over the blanket dose (100 kg·NPS·ha−1), 2.5 t/ha and 5 t/ha, respectively. It was also noted that resource-poor farmers, compared to unfertilized crop, can get grain yield superior by 130% and 214% using sole OF at 2.5 and 5 t·ha−1, respectively. Furthermore, the highest economic benefit (27, 179.5EtB) was recorded from 150 kg NPS/ha + 2.5 t·OF/ha. The finding suggested that locally available organic materials of plant origin alone/integrated with NPS fertilizer are helpful for increased yield of haricot bean
Extent, Distribution, and Causes of Soil Acidity under Subsistence Farming System and Lime Recommendation: The Case in Wolaita, Southern Ethiopia
No full textSoil acidity is one of the most important environmental threats to the Ethiopian highlands where the livelihood of the majority of people is reliant on agriculture. Yet, information regarding its extent, distribution, causes, and lime requirement at a scale relevant to subsistence farming systems is still lacking. This study (1) investigates the extent and spatial distribution of soil acidity, (2) identifies factors attributing to soil acidification, and (3) predicts the lime requirement for major crops. A total of 789 soil samples were collected from arable lands in the Wolaita area which is mainly characterized by poor soil fertility and soil degradation in southern Ethiopia. Results revealed that the landscape is characterized by a gentle slope followed by strongly sloppy > flat > hilly topographies. Clay is the dominant soil textural class. A soil pH map, which is generated using geospatial analysis, demonstrates that 3.3, 78.0, and 18.7% of the total area were under strongly acidic, moderately acidic, and neutral soil reactions, respectively. The exchangeable acidity (Cmol(+)/kg) varied from nil to 5.1, whereas exchangeable Al ranged from 1.4 to 19.9 Cmol(+)/kg. The soil pH has shown a significantly (p < 0.001) negative association with clay content (r = −0.33), exchangeable Al (r = −61), exchangeable acidity (r = −0.58), and inorganic fertilizer application (r = −0.33). Increased rates of diammonium phosphate (DAP) (r2 = 0.91) and urea (r2 = 0.88) markedly elevated soil acidity. Conversely, manuring showed a significant (p < 0.001) and positive relationship with pH (r = 0.37) in which the increasing rate of manure significantly reduced acidification (r2 = 0.98). DAP and urea applications above 75 kg/ha lowered soil pH units by 0.56 and 0.48, respectively, <25 kg/ha while at the same time farmyard manure (FYM) at 4 t/ha raised pH by 0.75 units over the unfertilized field. Residue management significantly (p < 0.001) influenced soil pH wherein it ranged from 6.09 (complete residue removal) to 6.61 (residue incorporation). Changes in land use, cropping intensity, and socioeconomic status were also significantly attributed to soil acidification. To curb the effects of soil acidity, the lime requirement for common bean growing fields varied from zero to 6.6 t/ha, while for maize it was between zero and 4.3 t/ha. It is concluded that soil management interventions such as maintaining and incorporating crop residues, integrated use of organic and inorganic fertilizers, liming, and enhancing farmers’ awareness should be advocated to overcome soil acidification and improve soil fertility. In addition, introducing crops with traits that tolerate acidity and Al toxicity is also suggested
Growth, Light Interception, Radiation Use Efficiency and Productivity of Mungbean [Vigna Radiata (L.) Wilczek] (Fabaceae) Cultivars as Influenced by Sowing Date
No full textThe purpose of this study was to assess the influence ofsowing date on growth, light interception, radiation use efficiency andproductivity of mungbean cultivars. The experiment comprised four sowingdates at ten days interval, viz. 08, 18, 28 July and 07 August 2006 and twocultivars, viz. Gofa local and MH-97-6. A randomized complete block designwith three replications was used. Early sown plants on 8th of July hadextended duration to attain physiological maturity, larger leaf area index(LAI) and greater dry matter accumulation. Moreover, early sown plantsexceeded in amount of light interception, radiation use efficiency (RUE) andgrain yield compared to the late sown ones. The RUE values were 1.74, 1.38,1.28 and 1.10 g DM MJ-1 for the first, second, third and fourth sowing dates,respectively. The decline in yield of last sown mungbean compared to firstsowing was about 2% per day of delayed sowing. Cultivar MH-97-6exceeded Gofa local in LAI and total dry matter. However, their differencesin cumulative intercepted PAR, RUE and grain yield were not statisticallysignificant. Grain yield was significantly correlated with growth periodmoisture (r=0.95), cumulative intercepted light (r=0.98), RUE (r=0.96) andLAI (r=0.82). Early July sowing gave superior performance among testedsowing dates of the main cropping season (meher). However, owing to thecrop’s short growth duration, it is worthwhile to do further research byincluding other sowing dates of the short rainy season (belg)
Farmers’ soil knowledge, fertility management logic and its linkage with scientifically analyzed soil properties in southern Ethiopia
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