Low available phosphorus (P) is one of the major hindrances to crop production in acid soils of western Kenya. Although considerable work has been done to establish P levels in the region, there is paucity of information on which to base fertilizer recommendations due to potential crop production differences caused by different soil types and climate. Phosphorus adsorption capacity and its relationship with some soil properties were evaluated in acid soils from nine locations of western Kenya. Adsorption data was obtained by equilibrating the nine soil samples with 30ml of KH2PO4 in 0.01 M CaCl2, containing 0, 80, 150 and 300 µg ml-1 for 48 hours with shaking for 30 minutes at intervals of 8 hours. Langmuir, Freundlich and Tempkin adsorption models were fitted to the test results and relationship between P adsorption and soil properties determined by correlations. The result of this study showed that the soils were strongly to extremely acidic (pH 4.83 - 3.76), had high exchangeable Al3+ (>2 cmol Al kg-1), Al saturation of (> 20% Al) and calculated maximal phosphorous adsorption varied from 770.83 to 1795.83 mg kg-1 soil. Comparing the models, Freundlich linear model showed a better fit to the tested soils compared to Langmuir and Tempkin models. The regression coefficients (R2) for the fitted Freundlich P adsorption isotherms was highly significant ranging from (0.995- 1.000) for all tested soils. Analysis of relationship between adsorption maximum and soil attributes revealed that adsorption maximum positively correlated with clay content, exchangeable P, exchangeable acidity and Aluminium saturation and negatively correlation with organic matter and electrical conductivity. Due to differences in maximal P sorption capacities within the tested area, blanket P fertilizer recommendation may affect crop productivity in some sites. There is therefore need for further research to determine optimal Phosphorus requirements for soils in each research site.
An experiment was carried out in Busia County, Kenya at Emalomba (N 00°25′28.8″ E 034°15′ 51.9″), Nambale District to assess the effects of nitrogen fertilizer rates and legume management options on nitrate nitrogen (NO3-N) under intercropping system. Six soybean residue management options were considered: Sole sorghum, sorghum + soybean left to maturity, sorghum + soybean mulched, sorghum + soybean incorporated, sorghum + soybean exsitu and sorghum + soybean exsitu and plot tilled. Three levels of nitrogen (0kg N ha-1, 40kg N ha-1, and 80kg N ha-1 as urea were applied as top-dress and treatments arranged in randomized complete block design. Soil NO3-N was significantly high (P<0.0010) in topsoil with a notable leaching to subsoil due to precipitation. Control treatments had low soil NO3-N in comparison to other treatments implying that, use of inorganic fertilizers to supplement soil N is important. Fertilizer application at 40kg N ha-1 with respect to on-farm soybean residue management was in relation to NO3-N supply was in the order: sorghum + soybean left to maturity > sorghum + soybean mulched = sorghum + soybean incorporated. Experimental plots with legume residues removed had significantly (P<0.001) low NO3-N. High leaf NO3-N observed points to transfer of N to sorghum by nitrogen fixation signifying importance of intercropping. There was no significant difference between nitrogen fertilizers applied at 40kg N ha-1 and 80kg N ha-1 irrespective of field managed legume residues. Sorghum intercropped with soybean left to maturity with nitrogen fertilizer applied at 40 kg N ha-1 reflected high (P< 0.001) soil NO3-N in comparison to the other management options. It is therefore recommended as a possible optimum rate and legume residue management option to improve soil NO3-N among small scale households with stretched socio-economic ability in Busia County.
Aims: Major and trace elements (Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni Pb, and Zn) were determined in 32 samples of ukwa, Treculia africana (African breadfruit). Study Design: The study was conducted on ukwa samples collected from 8 towns in Abia State, South-eastern Nigeria, between January and February, 2013. Methodology: Analysis of ukwa samples prepared using different methods (raw, dried, fried and boiled) was conducted using atomic absorption spectrophotometer after acid digestion. Results: The major elements contents (mgkg-1) of ukwa, irrespective of method of preparation, ranged from 3600-5500 for Ca, 1200-2100 for K, 660-1100 for Na and from 690-980 for Mg. The contents (mgkg-1) of Cu ranged from 10-28, 55-85 for Fe, 14-40 for Mn, 25-45 for Zn; Pb and Cd were <0.006; while Cr and Ni were <0.2 and <0.04 respectively. The methods of preparation did not significantly (P=.05) influence the levels of metals in breadfruits. Principal Component Analysis (PCA) showed that the elements tend to cluster in groups with Ca-Cu-Mg-Mn linked with the first varifactor, while pairs of Zn-Fe and Na-Fe were linked with the second and third varifactors respectively. Conclusion: The results of this study have shown that ukwa is a rich dietary source of Zn, Mn, Fe, Cu, Ca, Co, Cr, Mg, K, and Na without posing toxicological health risk due to Pb and Cd to consumers.
Soil salinity stress is a major problem for enhancing crop production and agricultural sustainability in arid and semiarid regions. In Egypt the area of irrigated land that is salt-affected is 33%. Field experiments was conducted at farmer's field, Koom Oshim, El–Fayoum governorate, Egypt during two successive seasons based on factorial completely randomized block design with three replicate. The research work aimed to study the effect of various levels of calcium (0 and 40kg fed-1), potassium (0, 40 and 80kg fed-1) combined with the foliar application of salicylic acid (0 and 0.05mM) on growth, yield, chlorophyll and nutrient content of Turnip and Chard grown in saline soil. The highest growth and yield parameter represented by root and shoot of Turnip and Chard was obtained with 40kg fed-1 applied calcium (Ca) and potassium (K) combined with 0.05mM salicylic acid (SA) as compared with same levels of Ca and K without SA and control treatment. At 40 days of sowing, Chlorophyll a and Chlorophyll b and carotene of Turnip and Chard significantly increased by Ca and K combined with SA application. Sodium (Na) accumulation in root and shoot of both Turnip and Chard decreased due to Ca and K application. K+, Na+, Ca++, ratios and selectivity increased in plant shoot due to decrease the Na accumulation in shoot as affected by Ca, K and SA application. Results concluded that Turnip and Chard could tolerate the soil salinity and produce higher yield under balanced application of Calcium and potassium combined with salicylic acid.
Biochar incorporation into soil has been shown to improve the soil quality for crop production and sequestered organic carbon into the soil thereby mitigating climate change. The experiment was conducted during 2010 rainy season at the research and teaching farm of the college of agriculture, Lafia, Nasarawa state, Nigeria. To evaluate the effect of biochar on soil properties and the amount of organic carbon that can be sequestered in the soil. The treatments consist of biochar rates: 0, 5 and10t/ha laid in Randomized Complete Block Design (RCBD).10t/ha of biochar produced the highest levels of (pH, = 6.91; %Total Nitrogen, =0.38; K, =1.59; %Organic Carbon, = 0.56; Mg, = 2.50 and Cation Exchange Capacity = 11.35) compare to the other rate and control. However, application of 5t/ha of biochar did not show any significant effect compared with the control. Biochar application did not show any significant effect on sand, clay and silt; but had a significant effect on % organic matter, bulk density and %porosity. Application of 10t/ha of biochar produced the highest value of 7.67% silt and clay; but sand particles and bulk density decreases with increased rates of biochar application. Therefore, the control produced soils with the highest values of sand particles of 87.33% and bulk density of 1.68g/cm. Also, there is a significant difference in total quantity of carbon sequestered at the different rates of biochar application. 10t/ha sequestered a largest quantities of 1352.40t/ha of soil organic carbon. The lowest carbon stored of 926.85t/ha was reported in control plot. The result of this study suggest that biochar additions to the soil produced general improvement of soil qualities, with the possibility of lowering the soil acidity and increasing organic matter and organic carbon sink which has the capacity to improve crop production and mitigate climate change.
Two field trials were carried out at the Agricultural Production and Research Station, NRC, Egypt, during the two successive summer seasons 2012 and 2013, to study the effect of combination between nitrogen fertilizer and foliar zinc application on growth, yield attributes and chemical constituents of groundnut seeds. Different treatments show significant differences in the both growth samples however, 120N kg.ha-1+1000 mg.L-1 zinc surpassed in most studied characters with no significant difference between this treatment and treatment 120N kg.ha-1+750mg.L-1 zinc in all studied characters. Increasing foliar zinc application from 0 to 1000mg.L-1 significantly increased all yield and yield attributes with the two nitrogen rates (60 and 120N kg.ha-1). Increasing foliar zinc application from 500 to 1000mg.L-1 with 60N kg.ha-1 shows significant differences in most studied characters, except weight of seeds.plant-1, 100-pod weight, 100-seed weight and pods yield.ha-1. Increasing foliar zinc application from 750 to 1000mg.L-1 with 120N kg.ha-1 shows significant differences in most of studied characters, except weight of seeds.plant-1, 100-pod weight and 100-seed weight. Significant differences between treatments in seed protein content, NP seed concentration and NK straw concentration.
Aims: The main aim of the study was to assess the effects of organic manure on nitrogen mineralization, uptake, use and recovery of cauliflower. Methodology: Nitrogen is one of the major yield limiting nutrients in cauliflower production. However, organic manure is applied to supplement soil nitrogen supply to maximize dry-matter yield. A field experiment was conducted at the Droevendaal Certified Organic Research and Demonstration Site of Wageningen University, Netherlands during 2012. The experiment was laid out in a randomized complete block design with four replications. The treatments comprised of four rates (0, 75, 150 and 225kgN.ha-1) each of lucerne pellets (LUP) and dry grass clover (DGC) organic manures. Results: Results showed that LUP amended plots exhibited highest initial N-mineralization compared to DGC and control plots. Nitrogen uptake in plant organs increased with increasing organic manure application. Nitrogen accumulation was highest in cauliflower leaf (38.28mg.kg-1), followed by the head (16.96mg.kg-1) and lowest in the stem (3.01mg.kg-1). Conclusion: Results suggest that timely and adequate nitrogen release from organic manures is important for the success of conservation and sustainable farming systems. Findings in this study could be utilized in improving efficiency of N use in crop management rotation systems.
A field study was conducted to investigate the effects of supplementary irrigation plus humic acid application on fruit yield, oil production and nutrient uptake of olive trees. Olive orchard located at Nabuls district, Palestine was used for conducting the field experiment during the growing period of 2011. Seventy-years-old olive trees “Souri cultivar” spaced at 10m×10m, were selected for the experiment. The field was divided into three treatments; with five replicates per each treatment. Each treatment has an area of one hectare with a plant density of 100 trees per hectare. Treatments consisted of application of three different irrigation water regimes as follows: Irrigation water plus humic acid, irrigation water only and no irrigation (rain-fed). Irrigation water was applied seven times at a rate of 430 l per tree, resulting in a total amount of three cubic meters per tree during summer months. Liquid organic fertilizer having 12% humic acid was applied with irrigation water once at a rate of 250cc per tree during the first irrigation application. Results of this study indicated that, the fruit yield of treatment irrigated with water plus humic acid was 78kg per tree, and 56kg per tree for treatment irrigated with only water, while the rain-fed treatment gave only 36kg per tree. Moreover, the higher oil yield was observed under water plus humic acid application (16kg per tree), while the rain-fed gave only (6kg per tree). In addition to that, the mean fruit weight of treatment irrigated with water plus humic acid was 2.1g, and 1.6g for treatment irrigated with only water, while the rain-fed treatment was 1.1g. The supplementary irrigation with three cubic meters of water per tree plus humic acid application have increased the fruit yield by 56.4% and oil yield by 62.5% compared to the rain-fed treatment.
Aims: Foliage plants production represents an important agricultural industry. Schefflera arboricola L. is an evergreen shrub in the family Araliaceae. The aim of the study was the evaluation of the effect of the substrate and the cutting type on the rooting process of schefflera. Study Design: The rooting test of cuttings involved 2 factors (rooting substrate and type of cutting) randomized block design with 4 replications plot with 9 cuttings. Place and Duration of Study: This trial was performed in the greenhouse of research Institute of Zabol University on May 2013. Methodology: Applique rooting beds were consisting of: R1: 100% perlite, R2: 50% perlite+ 50% cocopeat and R3: 100% sand. Three sorts of cutting were used in the experiment with different types of cutting (D1:4-7 mm as softwood, D2:8-11mm as semi-hardwood and D3:12-15mm as hardwood cuttings) for study type of cutting effect on rooting of cuttings. Results: The result of this test showed the effect of rooting substrate on all measured parameters (number of rooted cuttings, number of root in each cutting, total length, fresh and dry weight of roots) was significant; whiles the effect of type of cutting wasn’t significant on any characteristics. Interaction of rooting substrate and type of cutting was significant in 2 parameters (number of rooted cutting and number of root in each cutting). Perlite substrate was better than perlite-cocopeat and sand. Interaction of substrate and cutting type was significant between 3 substrates and 3 types of cutting, the best suitable treatment in interaction was for second type of cutting in perlite substrate, whiles it had significant difference to second type of cutting in perlite-cocopeat and sand substrate in number of rooted cuttings characteristics. So this trial eventuated that perlite substrate is better than the other substrates in rooting of schefflera cuttings in number of rooted cuttings, number of root in each cutting and length of roots.
Faba bean (Vicia faba L. var. Nobaria 12) was grown under saline irrigation water (1.0% Sea salt ECiw = 15.2dS m-1) and none saline water (Control, ECiw = 0.64dS m-1) and subjected to soil application of calcium (0,100 and 200ppm Ca as Calcium hydroxide) and foliar application of boron (0, 5 and 10ppm as boric acid). Results indicated that the reduction in growth and yield was found proportional with increasing salinity of irrigation water at all studied parameters but application of calcium and boron minimized the deleterious effects of salinity up to various extents. The significant improvement was observed in the shoot and root weight, chlorophyll content of leaves, due to the application of 200ppm calcium combined with foliar application of 5ppm boron under both non saline and saline conditions of irrigation water. Also, Pod and seed yield was increased as affected by Ca and B application under both saline and none saline irrigation water. In general, K+/Na+ and Ca2+/Na+ ratios of faba bean shoot was lower under saline irrigation water condition as compare to none saline water. Foliar spray of Boron at 5ppm was found much effective to minimize K+/Na+ and Ca2+/Na+ ratios and alleviating salinity hazard. Excess of Boron caused deleterious effects on plant growth indicating Boron toxicity at 10ppm B applied as foliar application.