Effect Of Different Rates Research Articles

English

The use of rootstocks in fruit production is extremely important, as well as reducing juvenility also enables faster production. In this context, the objective was to evaluate the effect of different rates of manure and application of organic fertilizer on the growth of guava rootstocks. The experiment was conducted in the greenhouse of the State University of Paraiba (UEPB) in municipality of Catole do Rocha-PB, Brazil. The experimental design was completely randomized (CRD), with in factorial 5 × 2, with 6 repetitions. The treatments consisted of the combination of manure proportions: (0, 20, 40, 60 and 80% v/v) mixture to the ground (2: 1 v v-1) and the second factor consisted of organic fertilizer application (with and without). 30, 60, 90 and 120 days after sowing (DAS) evaluated the following variables: plant height, leaf number, stem diameter, leaf area, root length, absolute growth rate and relative plant height , stem diameter and leaf area, dry matter of root mass, shoot dry matter mass, the total dry matter and Dickson quality index. The use of cattle manure at the rate of 80% positively influenced the growth of guava rootstocks with the application of organic fertilizer. Key words: Psidium guajava L., substrate, organic agriculture.

Behavior of Steel–Concrete Partially Composite Beams Subjected to Fire—Part 2: Analytical Study

This paper presents the development of an analytical model of steel–concrete partially composite beams subjected to fire. The model includes consideration of temperature dependent material properties, temperature dependent interface slip between concrete and steel, non-uniform temperature distributions throughout the cross-section and the effect of different rates of thermal expansion at the concrete–steel interface. Model predictions showed good agreement with the results of fire tests on two composite beams reported in an earlier companion paper as well as with limited experimental data published in literature. An extensive parametric study was undertaken by using the proposed model. Parameters considered in this study included geometric dimensions of the composite beam, material grades of steel and concrete, shear connection ratio, reinforcing steel ratio in the concrete slab, and load level on the beam. The parametric study clearly shows that shear connection ratio and load level significantly influence the fire performance of partially composite beams. The critical temperatures with shear connection ratio of 50%, 75% and 100% are 645°C, 602°C and 548°C, respectively, under load level of 0.6. The critical temperatures under load ratio of 0.5, 0.6 and 0.7 are 468°C, 553°C and 633°C respectively, with a shear connection ratio of 50%.

Prohexadione calcium affects shoot growth, but not yield components, of ‘Le Conte’ pear in warm-winter climate conditions

Different studies describing Prohexadione calcium (P-Ca) as an efficient tool to reduce shoot growth have been extensively reported, but these studies are usually performed in typical temperate climate regions. However, a complete analysis of the effects of P-Ca in pear trees in regions of warm-winter climates has not been performed. Therefore, the objective of this study was to evaluate the effect of different rates of P-Ca on vegetative growth, production and fruit quality of ‘Le Conte’ pear trees, in warm-winter climate conditions. The experiment was conducted during the 2013/2014 and 2014/2015 seasons, in a six year old ‘Le Conte’ pear orchard, trained to a central-leader system, with spacing of 1.5×4.8m, grafted onto Pyrus calleryana. Different P-Ca rates were applied (100, 200, 300, 400mgL−1) in different biological stages: first in early spring (shoots ∼2.5 and 5cm long) for all treatments and the others when shoot growth resumed (GR), but only for some treatments. Variables for vegetative growth, yield components and fruit quality at harvest and post-harvest were evaluated. Shoot length was measured on 10 one-year-old shoots evenly selected and tagged at the time of the first application and, then, at biweekly intervals until the end of the season. The use of P-Ca was effective to control vegetative growth in both seasons, at different rates. At ∼90days after full bloom (DAFB), P-Ca treated shoots had a pronounced second flush of growth, requiring an additional application of P-Ca in both seasons. In the 2013/2014 season, the only time of P-Ca reapplication was at 93 DAFB for the rates of 100 and 200mgL−1, which was enough to check shoot growth throughout the season, but in the 2014/2015 season, three shoot growth flushes were observed according to P-Ca rate, requiring additional P-Ca applications. Unlike the first season, P-Ca reapplication was efficient to reduce shoot length relative to trees treated once with P-Ca. In both seasons, fruit set, number of fruits per tree, yield, average fruit weight, fruit diameter, estimated yield, return bloom, and return yield were not affected by P-Ca applications. P-Ca applications did not alter the qualitative attributes of the fruits of ‘Le Conte’ pear trees at harvest and when they were stored for a period of 30days of regular air cold storage (RACS)+3days of ripening period (RP) in both seasons. These results implicate P-Ca as a potential tool to manage vigor of ‘Le Conte’ pear trees in warm-winter conditions, given its efficiency to control vegetative growth without negatively affecting yield components.

Effect of biochar application on soil hydrological properties and physical quality of sandy soil

Biochar is a valuable soil amendment and is recognized to have a positive effect on the crop yield, soil quality, nutrient cycling, and carbon sequestration. However, the effect depends on biochar characteristics, doses, and soil properties. This paper reports the study on determination of the effect of different rates of biochar based on their size fractions on water retention characteristic of sand-based rootzone mixture characteristic for natural turfgrass rootzone.The pot experiment was established using a soil with the texture of loamy sand. Mixtures of biochar and soil were prepared in March 2014. Biochar was produced using the straw of two species, namely miscanthus and winter wheat, by pyrolysis process at a temperature of 300°C for 15min with limited air access. Then, biochar particles were separated into three size fractions as follows: 0–500μm, 500–1000μm, and 1000–2000μm. The following four biochar rates were used in this experiment: 0.5%, 1%, 2%, and 4%.The results indicated that biochar application significantly improved the physical properties of the tested sandy soil. The basic soil physical parameters, such as bulk density and total porosity, were not only dependent on the rate but also on the size of the biochar. Small particles of biochar reduced the volume of soil pores in diameter below 0.5μm but increased the volume of larger pores with a diameter 0.5–500μm. Biochar application increased the available water content (AWC), especially when the finest fraction was used (0.064cm3cm−3). Biochar made of miscanthus was characterized by higher AWC (0.056cm3cm−3) than that made of winter wheat (0.050cm3cm−3). In the present study, the soil water repellency was increased by biochar application, but it was still classified as non-repellent.

Carbon sequestration and Jerusalem artichoke biomass under nitrogen applications in coastal saline zone in the northern region of Jiangsu, China

Agriculture is an important source of greenhouse gases, but can also be a significant sink. Nitrogen fertilization is effective in increasing agricultural production and carbon storage. We explored the effects of different rates of nitrogen fertilization on biomass, carbon density, and carbon sequestration in fields under the cultivation of Jerusalem artichoke as well as in soil in a coastal saline zone for two years. Five nitrogen fertilization rates were tested (in guream−2): 4 (N1), 8 (N2), 12 (N3), 16 (N4), and 0 (control, CK). The biomass of different organs of Jerusalem artichoke during the growth cycle was significantly higher in N2 than the other treatments. Under different nitrogen treatments, carbon density in organs of Jerusalem artichoke ranged from 336 to 419gCkg−1. Carbon sequestration in Jerusalem artichoke was higher in treatments with nitrogen fertilization compared to the CK treatment. The highest carbon sequestration was found in the N2 treatment. Soil carbon content was higher in the 0–10cm than 10–20cm layer, with nitrogen fertilization increasing carbon content in both soil layers. The highest soil carbon sequestration was measured in the N2 treatment. Carbon sequestration in both soil and Jerusalem artichoke residue was increased by nitrogen fertilization depending on the rates in the coastal saline zone studied.

EFFECT OF NITROGEN FERTILIZER ON GROWTH, YIELD AND YIELD COMPONENTS OF MAIZE (ZEA MAYS L.) IN DECHA DISTRICT, SOUTHWESTERN ETHIOPIA

Maize response to high nitrogenous fertilization levels is a means among other means to know maximum productivity, from this perspective, a field nitrogen management trial using five N levels (0, 23, 46, 69 and 92 kg N/ha) with three replications. The study was conducted in 2015 in Decha District, ModyoGomberaKebele of Kaffa Zone, SNNPR State. The experiment was laid out in RCBD. The result of this study indicated that effects of different rates of N fertilizer had influenced the growth and yield components of maize. The tallest plant (360.66 cm) was recorded from the application of 92 kg N ha-1 and the shortest (347.33 cm) from no N application. The ANoVA for the number of kernels per ear showed that the lowest kernels per ear (497.86) were obtained from no N application and the highest kernels per ear (588) were obtained from the application of 92 kg N ha-1 although there was no significant difference between the application of 69 and 92 kg N ha-1. Regarding to ear length the data showed that the longest ear (23.63 cm) was obtained from the application of 92 kg N ha-1. The effect of N on grain yield indicated that there is no significant difference between the application of 69 and 92 kg N ha-1 even if there is a slight difference on yield. Generally, maximum N fertilization level (92 Kg N/ha) in this study area showed increase in growth and yield components (number of kernels per ear and ear length). However the application of 69 kg N ha-1 seems adequate to get the optimum yield.

Modification of chemical and hydrophysical properties of two texturally differentiated soils due to varying magnitudes of added biochar

The potential benefit of biochar as a soil conditioner to improve crop yield and simultaneously sequester carbon in the soil, is a subject of intense discourse. Biochar amendment of agricultural soils is presumed to improve water holding capacity of the soil, and enhance nutrient retention within the root zone. However, there are very few investigations which provide quantitative data and qualitative descriptions concerning the specific mechanisms driving these improvements in the properties of biochar-amended soils. In this study, the effect of different rates of biochar amendment on some chemical, physical and hydraulic properties of fine-sand and sandy loamy silt soils was investigated by adding 20, 50 and 100g biochar kg−1 (by dry weight). In order to evaluate the additional effects of biochar application, the initial hydrophobicity and rheological properties were also examined. The result showed that biochar amendment improved total carbon and aggregate properties. The available water capacity was significantly higher in the amended substrates, particularly in the amended fine sand. Saturated hydraulic conductivity of the sandy loam silt increased between 25% and 119%, but decreased in the fine-sand between 23 and 82%. Moreover, biochar amendment of the sandy loamy silt improved particle to particle bonding and resulted in the development of weaker (compared with the unamended control) but more resilient aggregates which were better structured. With increasing rate of added biochar (≥50–≤100gkg−1) the added biochar itself now dominated the internal soil strength of the substrate. Adding (≥20gkg−1) biochar, to the fine-sand induced particle rearrangements, which in combination with possible surface oxidation at the biochar-soil particles interphase, improved bonding in this originally non-cohesive soil. Beyond an amendment rate of 50g biochar kg−1 soil, we observed that most of the positive improvements, associated with the biochar treatment of the soils, were no longer significant and the aggregates became brittle and collapsed more easily. Our results therefore provide more detailed insights into the effect of biochar in agricultural soils depending on texture of the soil and the amount of added biochar.

Effect of different rates of spent mushroom substrate on the dissipation and bioavailability of cymoxanil and tebuconazole in an agricultural soil

Physicochemical methods to immobilize pesticides in vulnerable soils are currently being developed to prevent water contamination. Some of these methods include the use of different organic residues to modify soils because they could limit the transport of pesticides and/or facilitate their dissipation. Spent mushroom substrate (SMS) may be used for these purposes. Accordingly a study was conducted under laboratory conditions to know the dissipation and bioavailability of the fungicides cymoxanil and tebuconazole over time in a vineyard soil amended with two rates of spent mushroom substrate (SMS) (5% and 50% (w/w)), selected to prevent the diffuse or point pollution of soil. The dissipation of cymoxanil was more rapid than that of tebuconazole in the different soils studied. The dissipation rate was higher in the amended soil than in the unamended one for both compounds, while no significant differences were observed between the amended soils in either case. An apparent dissipation occurred in the amended soil due to the formation of non-extractable residues. Bound residues increased with incubation time for tebuconazole, although a proportion of this fungicide was bioavailable after 303days. The major proportion of cymoxanil was tightly bound to the amended soil from the start, although an increasing fraction of bound fungicide was bioavailable for mineralization. Soil dehydrogenase activity was significantly affected by SMS application and incubation time; however, it was not significantly modified by fungicide application. The significance of this research suggests that SMS applied at a low or high rate to agricultural soil can be used to prevent both the diffuse or point pollution of soil through the formation of non-extractable residues, although more research is needed to discover the time that fungicides remain adsorbed into the soil decreasing either bioavailability (tebuconazole) or mineralization (cymoxanil) in SMS-amended soils.

Effect of Different Rates of Nitrogen and Phosphorous on Growth and Nodulation of Glycine max in the Eastern Region of Sri Lanka

An experiment was conducted to study the effects of different rates of nitrogen and phosphorous on the nodulation and growth of soybean. The pot experiment was conducted under a rain shelter in Agro Technology Park, Eastern University, Sri Lanka. The experimental design was CRD with four replicates. Different fertilizer combinations were used as treatments such as T1-30N:150P: 75K: kg/ha, T2-70N:150P:75K: kg/ha, T3 (control)-50N:150P:75K: kg/ha, T4-50N:125P:75K: kg/ ha and T5-50N:175P:75K: kg/ha. The results revealed that there were significant (p

Nutrient Availability of Tea Growing Soil Influenced by Different Rates of Dolomite

Teas ( Camellia sinensis L.) exclusively prefer to grow in acid soils but in very acidic nature it is detrimental to the available nutrient content especially Ca, Mg and Mn in soil. Dolomite is soil amendment which used to mitigate the soil acidity and also it provides some essential nutrient Ca and Mg itself. Present investigation was undertaken to identify the effect of different rate of Dolomite on major and micronutrient availability of Tea growing soils of low country wet zone. Field trial was laid out in Randomized Complete Block Design consisting of five treatments in different rate of Dolomite (kg/ha/pruning cycle) namely; T1 (control), T2 (1000), T3 (2000), T4 (3000), and T5 (4000). Soil nutrient content at 0-15cm and 15-30cm of depths were studied. The data generated from the study was analyzed by using Analysis of Variance (ANOVA) in SAS statistical package. Treatment means were compared at probability p< 0.05 using LSD. Soil Exchangeable Al, Ca and D.T.P.A extractable Mn were had no effect. But soil available Fe was significantly declined according to the dolomite rate. The highest average mean value of Fe was obtained in control. Highest average means of soil Exchangeable Mg (101.33mg/kg) was observed in highest dolomite applied plots at 0-15cm depth and highest K (130.67mg/kg) was recorded in the treatment with 2000kg/ha/pruning cycle.

Effect of different rates of nitrogen and potassium fertilizers on growth characters and leaf nutrient status of pear (Pyrus pyrifolia) cv. Patharnakh

Effect of different rates of nitrogen and potassium fertilizers on growth characters and leaf nutrient status of pear (<i>Pyrus pyrifolia</i>) cv. Patharnakh

Indigenous rhizobia population influences the effectiveness of Rhizobium inoculation and need of inorganic N for common bean (Phaseolus vulgaris L.) production in eastern Ethiopia

Supplement with inorganic N application is essential to improve the common bean production in sub-Saharan Africa. However, the influence of indigenous rhizobial population on the inorganic N requirement with Rhizobium inoculation to secure sustainable way of common bean production system is not well known. The effect of different rates of N application either alone or in combination with Rhizobium inoculation on the nodulation, yield and yield traits of common bean cultivated in soils with different rhizobial population were conducted. Twelve treatments were produced by factorially combined six levels of N fertilizer (0, 20, 40, 60, 80 and 100 kg N ha−1) and two Rhizobium inoculation treatments (inoculated and uninoculated). The treatments were laid out in randomized completely block design and all treatments were replicated three times. Regardless of soil types, nodule number and nodule dry weight decreased with increasing rates of N application. 20 kg N ha−1 both alone and in combination with Rhizobium inoculation resulted in the largest nodulation in all soil types. The largest nodulation were induced in soil with large rhizobial population. Rhizobium inoculation significantly (P < 0.05) improved yield and yield traits of common bean. Moreover, our result revealed that the largest values of investigated traits were observed in inoculated treatment, as compared to the corresponding N rates of uninoculated treatments. The 20, 100 and 40 kg N ha−1 treatments resulted in significantly greater plant total tissue N at soil types with small, medium and large rhizobial population, respectively, as compared to unfertilized control. The highest total biomass yield (TBY) and grain yield (GY) at soil types with small and medium rhizobial population were obtained by the 100 kg N ha−1 treatment in combination with Rhizobium inoculation, while 20 and 40 kg N ha−1 applications produced the greatest TBY and GY, respectively, in soil with large rhizobial population. These results indicate that N requirement is varied based on rhizobial population and effectiveness of native rhizobia in N2 fixation.

Planting row arrangement and nutrient management in geranium (&lt;italic&gt;Pelargonium graveolens&lt;/italic&gt;) -garlic (&lt;italic&gt;Allium sativum&lt;/italic&gt;) intercropping

Field experiments were carried out at Lucknow, India to evaluate the optimum plant row arrangement of geranium and to study the effects of different rates of fertilizer N, P and Zn for the yield assessment in a geranium-garlic intercropping system. A paired row arrangement (40/80 cm) of geranium planting significantly increased the herb and essential oil yield over the conventional single row planting method (60x30cm). The former gave 20.6 % more herbage than the geranium single row intercrop system, with a 22.3 % increase in oil yield. Application of N at 160 kg ha&lt;sup&gt;−1&lt;/sup&gt; significantly increased the herb and oil yields of geranium and bulb yield of garlic over the control and 80 kg N ha&lt;sup&gt;−1&lt;/sup&gt;. Uptake of N by geranium was also significantly higher at 160 kg N ha&lt;sup&gt;−1&lt;/sup&gt;. Application of phosphorus at 40 kg P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; ha&lt;sup&gt;−1&lt;/sup&gt; proved significantly better than the no P control in the production of geranium oil and garlic bulbs. Uptake of Zn increased significantly up to 40 kg P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; ha&lt;sup&gt;−1&lt;/sup&gt;. Higher rates of P decreased the Zn uptake by the plants. Application of 30kg ZnSO&lt;sub&gt;4&lt;/sub&gt;ha&lt;sup&gt;−1&lt;/sup&gt; showed a significant response on the herb and oil yields over the no zinc control. The higher growth indices such as monetary equivalent ratio (1.45), area time equivalent ratio (1.44), land use efficiency (144 %) and benefit cost ratio (6.37) were recorded with a geranium paired intercrop system compared to other cropping systems. The geranium paired intercrop system proved advantageous in enhancing the economic returns by 1.73 – a two fold increase over the geranium single row, sole cropping system. It is concluded from this study that intercropping of garlic with a geranium paired row system proved highly beneficial in terms of getting higher economic returns by almost a factor of two over the conventional geranium single row planting method. A fertilizer addition of 160 kg N, 40 kg P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; and 30 kg Zn SO&lt;sub&gt;4&lt;/sub&gt; ha&lt;sup&gt;−1&lt;/sup&gt; is recommended for achieving the maximum yield advantages in a geranium-garlic intercropping system.

Effect of Spacing and Nitrogen Fertilizer on the Yield and Yield Component of Shallot (Allium ascalonium L.)

This research was conducted to study the interaction effect of different rate of nitrogen fertilizer and plant spacing on yield and yield components of shallot under Jimma condition, in the experimental field of College of Agriculture and Veterinary Medicine, Jimma University. Local variety of shallot was used with the three level of nitrogen (0kg/ha, 100kg/ha, 150kg/ha) and three intra-row spacing (10cm, 15cm, 20cm). The result of this field experiment indicated that, the interaction effect of 150gk/ha and 20cm spacing resulted highly significant plant height (30.33cm) (p<0.05). Nitrogen levels significantly affected the number of leaves per plant of shallot with the highest value (27.84cm) obtained from 100 kg N ha -1 ,so statistically significant(p<0.05). There was no significant effect of interaction between nitrogen and intra-row spacing on leave number of shallot. Significantly largest stem diameter 0.63cm (p<0.50) was obtained from intra-row spacing of 20cm. But there was no interaction effect of nitrogen and spacing on the stem diameter of shallot. There was no interaction effect of nitrogen fertilizer and spacing on the bulb diameter of shallot. No significant difference was obtained with the interaction effect of nitrogen and spacing on shallot bulb weight. An increased N dose to 100kgha -1 resulted in the increased yield of shallot bulbs to 30.2 tha -1 which was significantly different from 0kgha -1 and 150kgha -1 (p<0.05). From this finding the highest growth performance of plant which leads to increased yield could be using 150kgha -1 and spacing of 20cm.However the conclusive recommendation should be based on the results of repeated experiments. Keywords: Shallot, Nitrogen, Spacing, Plant height, Leave number

Nitrogen and Potassium Topdressing in Maize Intercropped with Brachiaria Ruziziensis

Maize has been intercropped with different forage species, especially &lt;em&gt;Brachiaria&lt;/em&gt; spp., for different purposes and at different times: after maize harvest, as a food source for cattle; and exclusively for the production of straw to maintain a no-tillage system, which is the main purpose of intercropping in western Paraná. The objective was to investigate the effects of different rates of nitrogen (N) and potassium (K) topdressing on grain yield and components of yield for maize intercropped with &lt;em&gt;Brachiaria&lt;/em&gt;&lt;em&gt; ruziziensis&lt;/em&gt;. The experiment was conducted in Paraná State, Brazil. The experiment used a completely randomized block factorial design (4 × 3) with four replications. Treatments for the first factor consisted of sowing maize intercropped with &lt;em&gt;Brachiaria&lt;/em&gt;&lt;em&gt; ruziziensis&lt;/em&gt; with four rates of N topdressing (0, 80, 100 and 120 kg ha&lt;sup&gt;−&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;) applied as urea. For the second factor were rates of K topdressing (0, 30 and 50 kg ha&lt;sup&gt;−&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;), applied in the form of potassium chloride. During at sowing fertilization was performed with of 30, 26 and 50 kg ha&lt;sup&gt;−&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt; of N, phosphorus and K, respectively. The following variables were evaluated: plant height, first ear height, stem diameter, number of tillers per plant, mass of 1,000 grains, grain yield. The results showed that application of N topdressing promoted increased grain yield of maize intercropped with &lt;em&gt;Brachiaria&lt;/em&gt; &lt;em&gt;ruziziensis&lt;/em&gt; until N rate of 85 kg ha&lt;sup&gt;−&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;. Isolated application of K did not influence the variables studied.

Evaluation of Different Improved Upland Rice Varieties for Low Soil Nitrogen Adaptability

Scarcity of nitrogen fertilizer is a major constraint to rice production particularly in developing countries. Low soil fertility prevalent in farmer’s fields has led to low rice yields and the ever escalating fertilizer prices have made this important input unaffordable to most smallholder farmers who have limited resources for purchasing the required inputs. The Mwea Upland rice (MWUR) varieties were bred under low fertilizer input environment while other authors have indicated that the New Rice for Africa (NERICA) gives high yields under low input conditions. There is therefore need to identify the superior rice varieties that are adaptable to low nitrogen levels. Thus, the objective of this study was to investigate the effects of different rates of nitrogen fertilizer on improved upland rice varieties and identify the low input adaptable varieties. Field studies were conducted at Alupe in Western Kenya under rainfed upland conditions between August 2012 and April 2013. The experiment layout was split plot factorial in a Randomized Complete Block Design with three replicates. The main plot treatments were four rates of nitrogen fertilizer levels which were; 0 (control), 40, 80 and 120 kg ha-1 applied as calcium ammonium nitrate (26% N) in two equal splits; 21 days after sowing (DAS) and at panicle initiation (46 DAS). Sub-plots consisted of Original Research Article Sikuku et al; IJPSS, 5(1): 40-49, 2015; Article no.IJPSS.2015.058 41 four MWUR varieties namely MWUR 1, MWUR 2, MWUR 3, MWUR 4; and four NERICA varieties namely NERICA 1, NERICA 4, NERICA 10 and NERICA 11. The parameters measured included plant height, tiller number, filled grain ratio percentage and yield components. In the study, nitrogen treatment showed significant effect on plant growth and the measured parameters increased significantly with increase in nitrogen level. MWUR varieties studied were more adaptable to low nitrogen conditions as compared to NERICA varieties. The NERICA varieties recorded higher yield at high nitrogen levels as compared to MWUR varieties. However, NERICA 4 gave higher yield as compared to other NERICA varieties regardless of the nitrogen level. Results from our study suggest that MWUR 1 and 2 and NERICA 4 were more tolerant to low nitrogen as compared to MWUR 3 and 4 and NERICA 1, 10 and 11, because of higher height, more tiller number, higher filled grain ratio percentage and higher yield component as compared to the other studied varieties and may be suitable for soils low in nitrogen.

Effect of Cow Dung, NPK and Their Combinations on Soil Properties and Performance of Sweet Potato (Ipomoea batatas L.) in Sudan Savanna, Nigeria

In Nigeria, one of the major problems confronting agriculture is poor soil fertility replenishment strategy that could allow sustainable production. Two field trials were conducted simultaneously in Sokoto (UDUS, Vegetable Research farm) and Zamfara (Bakalori Irrigation Project) both in SudanSavanna agro-ecological zone of Nigeria, with the aim of studying the effect of different rates of cow dung, nitrogen-phosphorus-potassium fertilizer and their combinations on soil properties and performance of sweet potato. The research was conducted during the 2011/2012 dry season using ten treatments: 3, 2, and 1tons per hectare of cow dung, 400, 300, and 200 kilogram per hectare of nitrogen-phosphorus-potassium fertilizer, 2 tons of cow dung + 100 kilogram nitrogen-phosphoruspotassium fertilizer, 1.5 ton of cow dung + 150 kilogram of nitrogen-phosphorus-potassium fertilizer, 1 ton of cow dung + 200 kilogram of nitrogen-phosphorus-potassium fertilizer per hectare and no fertilizer application (control). The result obtained was consistent with regard to locations indicating a numerical increased in soil organic carbon, cation exchange capacity(CEC), total nitrogen, available phosphorus, exchangeable calcium and potassium due to the treatments Original Research Article Haliru et al; AJEA, 6(3): 189-195, 2015; Article no.AJEA.2015.078 190 application as compared to the initial values. However, the effect was not significant (p>0.05) among treatments. While on sweet potato yield the treatments effect was significant (p<0.05) and application of 300 kilogram of nitrogen-phosphorus-potassium fertilizer per hectare gave the highest sweet potato yield at both locations. This research therefore, recommended that treatments used are important materials for soil nutrients replenishment and application of 300 kilogram per hectare of nitrogen-phosphorus-potassium fertilizer is recommended for better sweet potato yield in the study areas.

Soil Microbial Community Structure and Target Organisms under Different Fumigation Treatments

Producers of several high-value crops in California rely heavily on soil fumigants to control key diseases, nematodes, and weeds. Fumigants with broad biocidal activity can affect both target and nontarget soil microorganisms. The ability of nontarget soil microorganisms to recover after fumigation treatment is critical because they play an important role in sustaining the health of agricultural and natural soil systems. Fumigation trial was conducted in Parlier, CA, and the study focuses on the effects of different rates of Telone C35 and also methyl bromide fumigation with polyethylene (PE) and totally impermeable film (TIF) tarps on target and nontarget soil microorganisms using field samples. Results indicated that the populations of target organisms, such asFusarium oxysporumandPythiumspp., were reduced at all rates of fumigants. Phospholipid fatty acid (PLFA) analysis indicated that all major nontarget soil microbial groups such as Gram positive bacteria, Gram negative bacteria, fungi, and arbuscular mycorrhizal fungi (AMF) were affected by methyl bromide (MeBr) fumigation treatment. In general, the effects of Telone C35 (299 L/ha) under PE tarp had the least impact on microbial community structure and better effect on controlling target microorganisms and, therefore, indicated the better option among fumigation treatments.

Effects of Chicken Manure on Growth and Yield of Jute Mallow (Corchorus olitorius L.) under Rain-Fed Conditions of Sudan

A field experiment was conducted in 2013 and 2014 cropping seasons at the Research and Teaching Farms of the Faculty of Agricultural and Environmental Sciences, University of Gadarif, to evaluate the effect of different rates of chicken manure on the growth and yield of jute mallow. The experiment consisted of four levels of chicken manure viz; 0, 5, 10, and 20 t/ha. The treatments were arranged in a randomized complete block design with three replicates. The results showed that increasing chicken manure significantly increased all the growth attributes of jute mall and resulted in an increase in crop yield and yield components in both seasons. The present study revealed that jute mallow has a positive response to chicken manure application which succeeded to compensate the deficiency of minerals in the Gadarif State of Sudan under rain-fed conditions. The study also recommend that the highest chicken manure application rate (20 t/ha) is indispensible for vigorous growth and substantial increase in jute mallow under harsh semi-arid conditions of Sudan.

The effect of different rates of weight gain on atrial electrophysiology

The effect of different rates of weight gain on atrial electrophysiology