Specific Fertilizer Recommendations Research Articles

A new approach to measure spatial variability of soil parameters and field technique to test-value specific fertilizer recommendations

<p>Information on the distribution of soil properties is important to know the status of nutrients in the soils based on which fertilizer nutrients are recommended. Given the variability of nutrients in the soils, making a site-specific fertilizer recommendation seems to be a compelling work. To determine the spatial variability of soil nutrients and to make judicious and precise fertilizer recommendations, new measures are designed with this study. These measures are tested against the soil samples (n = 43) for total nitrogen (N), organic matter (OM), phosphorus (P2O5), and potassium (K2O) in the study area. The descriptive statistical analysis indicated an average of low nitrogen and organic matter, while phosphorus was found to be very high and the level of potassium was high. The spread of nutrients across the data sets, however, included low, medium, high, and very high levels of ratings. The Deviation Square Index was developed and applied for the variability measurement and found that the largest variation was with phosphorus distribution, followed by potassium, nitrogen, and organic matter. The coefficient of variation (CV%) analysis also exhibited similar trends in nutrient distributions. Nitrogen was the main determinant explaining the variations in rice yield, while phosphorus and potash were negatively related to the yield. An index of fertilizer nutrient recommendation called Test-Value Specific Dose (TVSD) was developed and used to calculate the nutrient recommendation for each sampled location. This new method gave easy and more accurate doses of fertilizer over the blanket recommendation to fit the variations across the soil samples.</p>

Characterisation and Mapping of Soils in Major Coffee Growing Regions of Uganda

There is limited information on the soil nutrient status, site specific fertilizer and agronomic recommendations for coffee in Uganda hence limiting its production and productivity. Therefore, this study was undertaken to characterize the soils under coffee farms and provide fertilizer and land management recommendations for coffee farming in selected districts in Uganda. 717 soil samples were collected from 45 coffee growing districts that were purposively selected to represent the major coffee growing regions of Eastern, Northern, Western, Mid-west and West Nile. 35 districts were sampled from Robusta coffee growing areas and 10 districts from Arabica coffee growing areas. Parameters considered in the laboratory analysis included; pH, total organic carbon, total nitrogen, available P, exchangeable Calcium (Ca), Sodium (Na), Magnesium (Mg), and Potassium (K) and micro elements: Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn) and Boron, soil texture, bulk density and hydraulic conductivity. Soil nutrient levels distribution maps for Robusta and Arabica coffee growing regions were generated in ArcGIS for the entire country. The soil chemical and physical properties were subjected to analysis of variance using Genstat 14th edition. The soil mapping results showed that, the overall average soil macro-nutrients concentrations were significantly different across regions (p < 0.05) with Eastern having the highest levels of macro elements (CEC of 19.28 meq/100 g, Base Saturation (BS) of 43.40%, pH of 5.78, N of 0.20%, K of 1.64 meq/100 g, P of 107.68 mg/kg and OM of 3.31%) followed by Western region. No significant difference (p > 0.05) was recorded for the micronutrients across the different regions, except Zn (p < 0.05). This study showed that Phosphorus and Potassium were generally moderate to high levels in most of the regions sampled while Nitrogen and organic matter were moderate to low. Results from this study provide a general picture of the nutrient status across all coffee growing regions in Uganda and highlight the required modifications for increased production and productivity.

Grain yield and quality responses of durum wheat (Triticum turgium L. var. durum) to nitrogen and phosphorus rate in Yilmana Densa, Northwestern Ethiopia

Proper rate of fertilizer application is the major factor that affects yield and quality of durum wheat. Location specific fertilizer recommendation is lacking for durum wheat, therefore, nitrogen (N) and phosphorus (P) field experiment on durum wheat was carried out on farmer's field in 2017 and 2018 cropping seasons at Yilmana Densa district, Northwestern Ethiopia. The objective was to examine the response of durum wheat to N and P application and determine the optimal rate of nitrogen (N) and phosphorus (P) for durum wheat production in the district and similar agro ecology areas. Factorial combinations of four N levels (0, 90, 180 and 270 kg ha−1) and four P levels (0, 17.5, 35 and 52.5 kg ha−1) were evaluated in a randomized complete block design with three replications per site, over two sites in each year. Results indicated that N significantly affected most of the crop parametrs including grain yield, plant height, total number of tillers and effective tillers, spike length and seeds per spike, and the maximum value of the parameters recorded at the highest rate of N while application of phosphorus affected grain yield, plant height and spile length. The interaction effect of N and P significantly affected grain yield, plant height and seeds per spike. Grain yield showed quadratic and linear response to N and P application, respectively. The maximum grain yield (5182 kg ha−1) was obtained from the highest rate 270/52.5 N/P kg ha−1. The economic analysis revealed application of 270/52.5 N/P kg ha−1 gave the highest net benefit of 169741 ETB ha−1 with marginal rate of return 1453% and full fills the standard for quality of durum wheat production and hence can be recommended in Yilmana Densa District and other similar agro-ecologies in Ethiopia. The study revealed the need to further investigation for optimal N and P rates for different durum wheat varieties as they differ in protein content under the same management practices.

Response of Bread Wheat (Triticum aestivum L.) Varieties to Blended Fertilizer Rates on Quality Attributes and Economic Advantages

Bread wheat (Triticum aestivum L.) quality is an important component of the crop productivity as it improves both food security and income sources for farmers. However, its grain quality and economic yields are mainly constrained by poor soil fertility and lack of site specific fertilizer recommendation in the study area for specific variety. Therefore, a field experiment was conducted in Tiyo district of Arsi Zone, Ethiopia, on farmer's field in 2018 main cropping season in response of bread wheat varieties to blended fertilizer rates on quality attributes and its economic advantages. Factorial combination of two improved bread wheat varieties (Wane and Kingbird) and seven fertilizer treatments [Control, Recommended NP (150 kg ha-1 TSP (69%P2O5 ) + 158.7 kg ha-1 Urea (73 N)), 100 kg NPSB + recommended urea (46 kg N) , 150 kg NPSB + recommended urea, 200 kg NPSB + recommended urea, 250 kg NPSB + recommended urea, 300 kg NPSB + recommended urea.] were laid out in randomized complete block design with three replications. Results revealed that grain protein content and hectoliter weight were significantly affected by the main effect of varieties and fertilizer rates with highest grain quality obtained from Wane variety at 200 kg NPSB + 100 kg Urea ha-1 , and recommended NP fertilizer application. The partial budget analysis results revealed that the application of 200 kg NPSB ha1 + 100 kg Urea ha-1 on Wane and Kingbird varieties gave maximum marginal rates of return of 992.8% and 546.3% with highest net benefits respectively. Therefore, application of NPSB at the rate of 200 kg NPSB ha-1 + 100 kg Urea ha-1 in the production of Wane and Kingbird varieties produced better bread wheat quality and economic advantages for the experimental area of wheat production.

Effect of blended fertilizer types for improving production of sorghum (Sorghum bicolor L.) in Bena Tsemay district, Southwestern Ethiopia

Depletion of soil organic matter, depletion of macro- and micronutrients, lack of local specific fertilizer recommendation per commodity are among core constraints in Ethiopian soils that hinders crop production including sorghum. The experiment was conducted to evaluate blended fertilizer type effect on improving production of sorghum in Bena Tsemay district, Southwestern Ethiopia. The experiment was carried out in 2018 and 2019 main cropping season and laid out in RCBD following three replications with spacing of 75cm between rows and 20cm between plants. It was done by using control, (46N+68.7P2O5) kgha-1 , (142NPS+141Urea) kgha1 , (150NPSB+141Urea) kgha-1 , (160NPSBZn+144Urea) kgha-1 , (155NPSZn+141Urea) kgha1 , (197NPSBK+141Urea) kgha-1 and (207NPSBZnK+141Urea) kgha-1 treatments. Full dose of blended fertilizer, phosphorus, boron and potassium chloride fertilizers were applied at planting time and urea was applied in two split. Partial budget analysis with dominance and marginal analysis was done for economic evaluation. The result has revealed that sorghum has responded well to the application of macronutrients with micronutrients (Zn and B) than unfertilized. Application of 150kgha-1NPSB+141kgha-1Urea resulted in highest grain yield, while the lowest grain yield was recorded from the control. The highest economic returns of 230.06% was obtained from application of 150kgha-1NPSB+141kgha-1Urea; and it gives 43.85% yield increment and 31.86% increment in economic return over the control. Application of 150kgha-1NPSB+141kgha-1Urea was recommended for farmers and investor’s to produce sorghum on the study area and similar agro ecologies, as it was optimum for improving sorghum production. Further investigation should be done on plant nutrient uptake, nutrient use efficiency and optimization.

Grain Yield and Yield Components Response to Omission of Nutrients on Maize (Zea Mays L.) at Kersa District, Jimma Zone, Ethiopia

The nutrient supply capacity of a soil varies with soil types as well as with farmers’ crop management practices. Yet fertilizer application in Ethiopia is based on regional recommendations, which do not take in to account the variability in soil types as well as farmers’ crop management practices. Thus, site specific fertilizer recommendation that considers soil variability and difference in farmers’ crop management practices is quite important. A field experiment was conducted with an objective to identify which of macronutrients N, P and K are limiting maize grain and yield components in the study area during 2017/18 cropping season. The experiments were laid out in a completely randomized block design with six treatments replicated across six farmers’ fields in Kersa district, Jimma zone, south western Ethiopia. The trial consisted of six treatments, which include the unfertilized control, PK, NK, NP, NPK and NPK+. Maize grain yield was the highest for the NPK treatment followed by NPK+ treatment but lowest for the unfertilized control and N omitted plots. The magnitude of grain yield reduction due to nutrient omission followed the trend of N omission> P omission> K omission. In the absence of N, P, and K maize grain yields were significantly lower compared to that of NPK and NPK+ treatments. From among the different treatments, NPK gave the highest grain yield(9185 kg ha -1 ), while the control treatment gave the lowest grain yield (1861.3 kg ha -1 ).Grain yield levels obtained for different fertilizer treatments were ranked as NPK > NPK+>NP>PK>NK, illustrating that N deficiency was the most yield limiting nutrient followed by P and K in that order. Therefore, the use of appropriate balanced fertilizers should be used for efficient nutrient uptake which ultimately increases maize productivity. Keywords: Maize, Nitrogen, Nutrient omission, Phosphorus, Potassium DOI: 10.7176/JEES/11-8-04 Publication date: August 31 st 2021

Establishment and validation of site specific fertilizer recommendation for increased barley (Hordeum spp.) yield, northern Ethiopia

Establishing model based balanced nutrient requirements for barley (Hordeum spp.) in the northern Ethiopia can solve the fertilizer recommendation problems and enhance crop yield. The Quantitative Evaluation of Fertility of Tropical Soils (QUEFTS) model was used to estimate balanced nitrogen (N), phosphorus (P) and potassium (K) requirements for barley production in Alaje, northern Ethiopia. The objectives were to (i) quantify soil N, P and K supply and recommend fertilizers using QUEFTS model; (ii) investigate response of QUEFTS fertilizer application on yield and nutrient uptake and (iii) validate QUEFTS model performance. The experiment had four treatments: (T1) model based fertilization; (T2) blended fertilization; (T3) farmers’ fertilization practices and (T4) control/no fertilizer. Soil information of the experimental plots were analyzed and used as model input to estimate soil nutrient supplies and recommend fertilizer. Yield and agronomic data were recorded and nutrient uptake and use efficiencies were analyzed. Model performance and accuracy were also checked using root mean square error, coefficient of determination, index of agreement and percent bias. The result revealed that the N, P and K soil supply ratio in the field experimental plots were 9:1:6. The higher grain yield of 4747 kg ha−1 was recorded in the QUEFTS based fertilization plots. Validation results indicated that there is a good correlation between the QUEFTS predicted and observed grain yields implying that the QUEFTS model can be a base for development of simple and cost-effective decision support tools for nutrient management and fertilizer recommendations. Thus, the model performance and prediction accuracy is promising and can help farmers to adjust fertilizer application rates based on crop requirements.

Effect of Inorganic Fertilizer and Sowing Methods on Tef (Eragrostistef (Zucc.) Trotter) Production in Ethiopia: Review

Tef [Eragrostistef (Zucc.) Trotter] is one of the major small cereal crops in Ethiopia in terms of production and consumption. But in Ethiopia, it is yield low as compared with other major cereal crops growing due to many production constraints such as low soil fertility, lack of appropriate management practices, minimum use of improved varieties, and lack of location specific fertilizer recommendation. Synthetic fertilizer and sowing method have great role on yield and yield components of Tef. So, objective of this study is to review the effects of inorganic fertilizer and sowing methods on yield and yield components of Tef in Ethiopia. Most research work so far focused on NP requirements of crops, but limited information is available on various sources of fertilizers like S, Zn, B and other. Tef responds differently to fertilizer rates and types depending on soil type and cultivars. Application of other sources of nutrients beyond urea and DAP, especially those containing S, Zn, B and other micro-nutrients and different method of sowing could increase Tef crop production and productivity in different area and different agro ecology. Therefore, to increase the production and productivity of tef in country use of Synthetic fertilizer and row sowing are important. Keywords : Inorganic Fertilizer, Sowing Methods, Yield DOI: 10.7176/JNSR/12-4-03 Publication date: February 28 th 2021

Soil analysis is pivotal for fertilizer recommendations: Comment on “Soil based, field specific fertilizer recommendations are a pipe-dream” by A.G.T. Schut and K.E. Giller. Geoderma (https:/doi.org/10.1016/j.geoderma.2020.114680)

Soil analysis is pivotal for fertilizer recommendations: Comment on “Soil based, field specific fertilizer recommendations are a pipe-dream” by A.G.T. Schut and K.E. Giller. Geoderma (https:/doi.org/10.1016/j.geoderma.2020.114680)

Comment on “Soil based, field specific fertilizer recommendations are a pipe-dream” by A.G.T. Schut and K.E. Giller. Geoderma (https:/doi.org/10.1016/j.geoderma.2020.114680)

Comment on “Soil based, field specific fertilizer recommendations are a pipe-dream” by A.G.T. Schut and K.E. Giller. Geoderma (https:/doi.org/10.1016/j.geoderma.2020.114680)

Effect of Nitrogen Fertilizer Levels and Row Spacing on Yield and Yield Components of Upland Rice Varieties in Pawe, Northwestern Ethiopia

Rice (Oryza species) is a major cereal crop in Pawe area. However the yield of the crop is low due to lack of site specific row spacing and fertilizer recommendation. Hence, a field experiment was conducted in Pawe Agricultural Research center during the rainy season of 2016 to assess the effect of row spacing and nitrogen fertilizer level on grain yield and yield component and to determine their economic feasibility on up-land rice varieties under rain-fed conditions. Two varieties (NERICA-4 and Pawe-1), three row spacing (RS) (20, 25 and 30 cm) and four N levels (0, 32, 64 and 96 kg ha -1 ) were laid out in Randomized Complete Block Design in factorial combination with three replications. Among the main treatment, variety NERICA-4 showed significantly taller plant height and panicle length. Interaction effect of variety, RS and N levels highly significantly (P < 0.01) affected the number of total tiller m -2 (NTT), fertile tiller 0.5 m -2 row length (FT), thousand kernels weight (TKW), above ground dry biomass yield, straw yield (STY) and harvest index, and significantly (P<0.05) affected grain yield (GY) ha -1 . The highest (420.0 m -2 ) NTT was found by variety NERICA-4 at 20 cm RS and 96 kg N ha -1 . The highest GY (6462.56 kg ha -1 ) was obtained by variety NERICA-4 at RS 20cm and 96 kg N ha -1 and the lowest GY (1935.5 kg ha -1 ) was obtained by variety Pawe-1 at RS 30 cm and no N input. The highest STY (8477.2 kg ha -1 ) was produced by variety Pawe-1 at 20 cm RS and 96 kg N ha -1 . The attractive net benefit (32,063.8 birr ha -1 ) with acceptable marginal rate of return (453.4%) for farmers in Pawe was found from variety NERICA-4 interacts with RS 20 cm and 96 kg N ha -1 . Keywords : - Biomass Yield, Grain Yield, Interaction effect, NERICA-4, Net benefit. DOI: 10.7176/JNSR/10-11-01 Publication date: June 30th 2020

Assessment and Mapping of Soil pH and Available Phosphorus Status in Wuchale District, North Shewa Zone, Oromia

The lack of site specific fertilizer recommendation to replenish declining soil fertility has been the major challenge to boost crop production in Ethiopia. Therefore, an investigation was conducted on soil pH and Av. P status assessment and mapping at wuchale district. About One hundred sixty one (161) geo–referenced soil samples were collected by using grid survey method. For both soil parameter analysis standard laboratory analysis were followed. In order to predict values for not sampled locations the Ordinary Kriging interpolation was used by ArcGIS10.3 software. The pH of the soil samples ranged from 4.84 to 6.67 and about 98.13% of all agricultural soils were acidic in reaction. The district has three categories of soil pH but the majority of the area falls in moderately acidic, strongly acidic and neutral soil pH which account area share of 51.55%, 46.58% and 1.87% respectively. Available P ranged from 2 to 64.79 ppm. The available phosphorus level is categorized as low, medium and high which is 26.70%, 52.80% and 20.50% respectively. The dominating class is medium i.e. (5 to 15ppm). Appropriate rate of lime needs to be applied or cultivating acid tolerant crops is recommended for both strongly acidic and moderately acidic soils of the study district to obtain optimum crop yields. The areas which are low in available soil phosphorus level need to be improved by adding organic manures (FYM/Compost) and inorganic fertilizers to boost the agricultural productivity of the study areas.

The potential for using smartphones as portable soil nutrient analyzers on suburban farms in central East China

Soil testing is frequently conducted to specify nutrient supply recommendations. By adjusting fertilizer type and application rates, farmers can achieve desired crop yields with lower production costs and are thereby less likely to contribute to eutrophication of nearby waterbodies. However, traditional methods of soil testing can be costly, time-consuming and are often impractical in rural and resource-poor regions in China, where rapid population growth and consequent food demand must be balanced against potential environment risks. Smartphones are nearly ubiquitous and offer a ready capability for providing additional support for existing extension advice. In this study, we used an Android-based smartphone application, in conjunction with commercially-available Quantofix test strips, to analyze soil samples with a goal of providing specific fertilizer recommendations. The app transforms the smartphone into a portable reflectometer, relating the reaction color of the test strips to the concentration of soil nutrients available. A 6-month long field study involving two growing seasons of vegetables was conducted in a suburban area of Nanjing, Jiangsu Province of China to evaluate the accuracy and precision of smartphone-mediated soil analysis. Results obtained via the smartphone correlated well with the yield response of the common green vegetable Ipomoea aquatica (water spinach) and could be applied in calculations of necessary off-farm inputs throughout the open-field vegetable growing season. Together, the smartphone and test strip in combination were shown to offer an acceptable screening tool for soil nutrient concentration assessment with the potential to result in substantial monetary savings and reduction of nutrient loss to the environment.

Pengujian Rekomendasi Pemupukan Spesifik Lokasi dan Sistem Tanam terhadap Hasil Padi Sawah di Desa Temega, Kecamatan Abang, Karangasem

Evaluation of Specific Location Fertilizer Recommendations and Plant System on Rice Yield Temega Village, Abang District, Karangasem. This study aims to determine the response of specific location fertilizer recommendations and planting system on rice yields in Temega Village, Abang District, Karangasem Regency. The method was used Factorial Randomized Block Design (RBD). The treatment tried consisted of two factors. The first factor was fertilization recommendations (R): R1 = location specific recommendation (250 kg Urea/ha, 100 SP36/ha and 50 kg KCl/ha); R2 = Location specific recommendation + Compost (230 kg Urea/ha, 100 SP36/ha, 50 kg KCl/ha + 5 t compost/ha), R3 = Farmer method (300 kg Urea/ha, 125 SP36/ha and 75 kg KCl/ha). The second factor was planting system (TL) : T = Tegel (20 cm x 20 cm) and L = Jajar Legowo 2 : 1. Combination of treatments into 6 treatments and each treatment was replicated 4 times so that there were 24 plots of research. The results showed that location specific fertilizer recommendations resulted in oven dry grain weight m-2 of 0.84 kg compare to that of farmers (0.85 kg). The application of location specific fertilizer recommendations can save as much as 50 kg Urea/ha, 25 kg SP36/ha and 25 kg KCl/ha. Jajar Legowo planting system can produce grain contain m-2 of 1.14 kg or an increase of 78.13% compared to tegel planting system (0.64 kg).

Effects of Different Level of Nitrogen Fertilizer Application on Growth, Yield, Quality and Storage Life of Onion (Allium cepa L.) at Jimma, South Western Ethiopia

Onion (Allium cepa L.) is one of the most important vegetable crops produced in Ethiopia. Yield and productivity of the crop has been far below the regional and national standards owing to several factors; absence of location specific fertilizer recommendation being the major among others. In Ethiopia, post harvest loss of vegetables contributed up to 30% yield reduction. Thus, a field experiment was conducted at Jimma University College of Agriculture and Veterinary Medicine Research field during dry season to study the effects of Nitrogen fertilizer application on growth, yield, quality and storage life of irrigated onion under Jimma condition, South Western Ethiopia. The treatments consisted of four levels of Nitrogen (0, 50, 100 and 150 kg N ha -1 ) that laid out in Randomized Complete Block Design with three replications. Data on growth, yield, bulb quality and storage life parameters were recorded and analyzed using GenStat 12.1 version computer soft ware packages. Results of the study revealed that; Nitrogen fertilizer applications had shown a highly significant effect on growth, yield and quality of onion. Similarly, the keeping qualities of the Onion bulbs are highly influenced by application of N at different levels. Excessive application of Nitrogen fertilizer caused higher bulb rots (%); bulb sprouts (%) and weight loss (%) during the three month storage time at ambient temperature. This can be recommended for use by potential onion investors or farmers in the study area. Keywords : Growth, Nitrogen, Onion, Quality, Storage life, Yield. DOI : 10.7176/JNSR/9-10-05 Publication date :May 31 st 2019

Soil health card development for efficient soil management in Haryana, India

Soil health card (SHC) based management is needed for efficient management of resources and sustainable crop productivity. Soil health index (SHI) could be used as a yardstick for judging the health of the soil. Soil management and assessment framework (SMAF) is widely used to develop soil health indices to assess the impact of different management practices in cropping systems. The three steps used under SMAF are indicator selection, indicator interpretation, and indicator integration into a unified soil quality index. Soil samples were collected from farm fields with diverse management histories. This included application of farm yard manure (FYM), green manure (GM), no manure (NM). The tillage practices used by the farmers were direct seeded rice followed by zero tillage wheat (DSR-ZT), conventional tillage rice followed by zero tillage wheat (CT-ZT), system of rice intensification followed by zero tillage wheat (SRI-ZT) and CT rice followed by CT wheat (CT-CT). The soils were analysed for pH, electrical conductivity (EC), soil organic carbon (SOC), Active carbon (AC), available nitrogen (Av-N), phosphorus (Av-P), potassium (Av-K), iron (Av-Fe), manganese (Av-Mn), zinc (Av-Zn), copper (Av-Cu), bulk density (BD), maximum water holding capacity (MWHC), aggregate stability (AS), microbial biomass carbon (MBC), dehydrogenase activity (DHA), potentially mineralizable nitrogen (PMN). Minimum data set (MDS) decided in conceptual framework (CF) were further reduced by principal component analysis (PCA). The PCA screened SOC, Av-Zn, Av-Mn, Av-K, AS, MBC and PMN as most sensitive soil health indicators. The SHI developed by CF and PCA were significantly correlated with each other suggesting that PCA approach with limited soil parameters could be adequately applied for development of SHI. There were enough variations in the MDS for developing scoring curves that facilitated successful scoring of the data. Native soil texture significantly influenced the SHI; sandy clay loam soil showed highest SHI (0.67) followed by sandy loam (0.57), loamy fine sand (0.44), and fine sand (0.35) soils. Among the manuring management practices, GM showed the highest SHI (0.56) followed by FYM (0.49) and NM (0.47). Among the tillage practices, DSR-ZT showed highest SHI (0.76) followed by CT-ZT (0.59), SRI-ZT (0.55) and CT-CT (0.49). The soil health card developed has vital information on farmers, field location, soil type, and cropping practices. The soil health card also has information on eleven chemical indicators, four physical indicators and three biological indicators and SHI. The SHC has additional advantage over routine soil testing in terms of presenting information on health status of the soil as impacted by different management practices, amelioration recommendations and crop specific fertilizer and manure recommendations.

Increased Maize Yields through the Transdisciplinary Process with Site Specific Fertilizer Recommendation in Small Holder Farms in Uasin Gishu County, Kenya

The objective of this study was to evaluate the effects of site-specific fertilizer recommendations on maize yield using the transdisciplinary (TD) process. 144 farmers participated in the study for the two seasons. Experiments were laid on the farmers’ fields at four sites (Kapyemit, Kipsomba, Ngenyilel and Ziwa, in Uasin Gishu County) using Randomized Complete Block Design in a 3 x 2 factorial arrangement. Treatments included farmers who participated in the TD process (TD2) and those who did not (TD1) in using the interventions for soil fertility improvement which were farmer own practices (ST1); farmers who applied government recommendations (ST2), and site-specific fertilizer recommendations (ST3) which was based on soil testing results. The Data collected was the dry weights of maize which were measured at the end of the seasons and subjected to Analysis of Variance using Genstat 14th edition. Means separation was done using Fischer’s unprotected Least Significant Difference.. There was a significant effect on maize yields by soil testing and participation in TD process p = 0.01. The mean maize grain yield for season one was 5.43 ton ha-1 while for season two was 5.73 ton ha-1. Control farmers (TD1) maize grain yield of 5.27 ton ha-1, had a significant difference (p = 0.05) from the yield of participating farmers (TD2) who had 5.96 ton ha-1. Maize grain yield was increased by the application of site specific fertilizer recommendations which gave an overall mean of 6.57 ton ha-1 for season one and 6.56 ton ha-1 for season two. Following (ST3) recommendations and participation in the TD process, improved soil nutrient content thus maize yield increased. We recommend soil testing and consequent site-specific fertilizer recommendations for any initiative in managing soil fertility.

Effect of Phosphorus Fertilizer for Maize Production in Gimbo Woreda at Kafa Zone Southern Ethiopia

The current use of commercial fertilizers in Ethiopia is not in harmony with the economics. Although, there have been nitrogen and phosphorus fertilizer rates for the production of maize, sometimes this recommendation does not work outside the experiment sites largely due to the variation of the soil fertility levels on farmer’s field. Therefore, site specific fertilizer recommendation and continual updating and re-evaluation of this recommendation are a vital step for optimizing the maize grain yield. Although field experiment results are more reliable, soil test calibration research could alleviate this problem with much more benefit to farmers and the environment the average national yield. The objective of this study was to assess and evaluate phosphorus fertilizer requirement for Maize. Seven levels of P (0, 10, 20, 30, 40, 50, and 60) combined with sufficient amount of N 46kg and laid down in RCBD with two replication. The experiment was conducted for two consecutive years at Kaffa Zone Gimbo Wereda.TSP was used as a source of P and Urea was used as a source a common combined N. All dose of P was applied at planting while N was applied as splitting half at planting and half after 45 days of planting crop data such as plant highest, stand count at emergency, stand count at harvest,biomass,grainyield,cobelength and 1000seedweight was collected and analyzed using SAS computer software . Composite surface soil samples (0-20 cm) were collected before planting, at harvest from each treatment. The highest maize production of grain yield was obtained from 30kg P ha -1 and 50kg P ha -1 on two 2005/6 and 2006/7 consecutive years respectively. So that these levels are better for maize production .but for economic value 30kgPha -l1 should be recommended for better maize production approach. Keywords: P fertilizers, Maize production DOI : 10.7176/FSQM/85-05 Publication date :March 31 st 2019

Yield Response and Nutrient Use Efficiencies under Different Fertilizer Applications in Maize (Zea mays L.) In Contrasting Agro Ecosystems.

Variability in crop response and nutrient use efficiencies to fertilizer application is quite common under varying soil and climatic conditions. Understanding such variability is vital to develop farm- and area- specific soil nutrient management and fertilizer recommendations. Hence the objectives of this study were to assess maize grain yield response to nutrient applications for identifying yield-limiting nutrients and to understand the magnitude of nutrient use efficiencies under varying soil and rainfall conditions. A total of 150 on-farm nutrient omission trials (NOTs) were conducted on farmers’ field in high rainfall and moisture stress areas. The treatments were control, PK, NK, NP, NPK and NPK+ secondary and micronutrients. Maize grain yield, nutrient uptake, agronomic and recovery efficiencies of N and P differed between fertilizer treatments and between the contrasting agro-ecologies. The AEN ranged from 24.8 to 32.5 kg grain kg-1 N in Jimma area and from 1.0 kg grain kg-1 N (NK treatment) to 10.2 kg grain kg-1 N (NPK treatment) at Adami Tullu and from 0.1 kg grain kg-1 N (NK treatment) to 8.3 kg grain kg-1 N (NPK treatment) at Bulbula. The differing parameters between the agro-ecologies were related to difference in rainfall amount and not to soil factors. Grain yield response to N application and agronomic efficiencies of N and P were higher in the high rainfall area than in the moisture stress areas. Grain yield responded the most to nitrogen (N) application than to any other nutrients at most of the experimental sites. Owing to the magnificent yield response to N fertilizer in the current study, proper management of nitrogen is very essential for intensification of maize productivity in most maize growing areas of Ethiopia.

Effects of different levels of potassium fertilization on yield, quality and storage life of onion (Allium cepa L.) at Jimma, Southwestern Ethiopia.

In Ethiopia the yield of Onion (Allium cepa L.) is far below the national standards owing to several factors; absence of location specific fertilizer recommendation being the major among others. Thus, field and laboratory experiments were undertaken at Jimma in collaboration with Jimma University, Department of Post-harvest Management. Potassium sulphate fertilizer as TSP was used at 0, 40, 80 and 120 kg ha-1 levels with three replications. GenStat 12.1 version computer software packages were employed to analyze the data. From the results potassium fertilizer application at different levels showed significant effects on growth, yield and quality parameters i.e. Plant height, leaf length, leaf number, sheath length, bolters percentage, days to maturity, harvest index, mean bulb weight, bulb length, bulb diameter, TSS (oBrix), DMC (%) and bulb shape index. Similarly, keeping quality of the onion bulbs including bulb sprouts (%), weight loss (%), weeks to 50% bulb sprouts and storage rots (%) were highly influenced by application of K at different levels. Maximum (120 kgha-1) application of potassium significantly decreased bulb rots (%), bulb sprouts (%), weight loss (%) and prolonged weeks to 50% bulb sprout during the two month storage time at ambient storage temperature and humidity. This could be recommended for the uses by potential onion investors or farmers in the study area. Nevertheless, more researches are needed in different locations and on different soils in various season to come up with specific soil test based fertilizer recommendation.