Application Of Different Rates Research Articles

Phytochemical screening and insecticidal activities of some medicinal plants against the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae)

This study emphasizes the phytochemical study of some locally available botanicals against maize weevils. Nine plant parts were collected from six plant species. The test plant powder (200 g) was suspended sequentially in 600 ml of petroleum ether, chloroform, acetone, methanol, and distilled water for 72 h with frequent agitation. Different concentrations of the crude extracts were applied to maize seeds at rates of 10 ml, 15 ml and 20 ml per 100 g. All treatments with different extracts at different rates of application showed significant differences (p < 0.05) in the cumulative mean percentage mortality of the maize weevil. The seed extract of Maesa lanceolata and Croton macrostachyus and the leaf extract of Clausena anisata showed cumulative percent mortality ranged 95.32–98.02% in 28 days after treatment application. There was no significant difference (p > 0.05) among all treatments for the prevention of F1 progeny emergence. In all extracts, Clausena anisata showed 100% inhibition of F1 progeny emergence. All treatments significantly reduced seed weight loss and damage. The treated maize seeds were germinated with an acceptable germination quality. In conclusion, an increased dosage of the extract resulted in significant mortality in maize weevils. The seed extracts of Maesa lanceolata and Croton macrostachyus and Clausena anisata leaf extract were observed to be the most promising botanical in protecting stored maize against maize weevil.

Урожайность сортов сои в Центральном Нечерноземье при использовании различных норм внесения регулятора роста

Abstract. When growing environmentally friendly soybean products, it is necessary to use safe and low-hazard fertilizers, plant protection products and biostimulants. Their use increases productivity, reduces cultivation costs and produces high-quality products. The purpose of the research was to study the influence of different rates of application of the growth regulator “Zerebra Agro” on plant growth, the formation of the symbiotic apparatus, the size and quality of the soybean yield. Research methods. On the base of three years of research, an analysis was made of the influence of growth regulator application rates on the symbiotic apparatus, yield and quality of soybean seeds. Scientific novelty. In the weather and climatic conditions of the Non-Chernozem Zone of the Kaluga Region, the optimal rate of application of the growth regulator “Zerebra Agro” to increase soybean yields was determined for the first time. Results. Spraying vegetative plants of the Georgia variety at a rate of 0.10, 0.15 and 0.20 l/ha contributed to an increase in plant height by 3.6–6.3 cm, leaf area by 7–16 %, dry aboveground mass by 5–10 %, underground mass – by 6–12 %, and in the Pripyat’ variety – an increase in plant height by 2.7–4.6 cm, leaf area – by 2–6 %, dry aboveground mass – by 3–6 %, underground mass – by 3–7 %. In the studied soybean varieties, the number and weight of nodules significantly increased when treated with the drug at a rate of 0.10 and 0.15 l/ha. The use of the growth regulator “Zerebra Agro” contributed to an increase in the seed yield of soybean varieties: Georgiy by 0.12–0.80 t/ha, and Pripyat’ by 0.24–0.54 t/ha. A significant increase in yield by 0.8 t/ha and protein content in seeds by 1.3% was noted when plants of the Georgia variety were treated at a dose of 0.20 l/ha. In the Pripyat’ variety, an increase in the protein content in the seeds was noted in all variants of using the “Zerebra Agro” preparation.

Alkaline humic acid fertilizer alters the distribution, availability, and translocation of cadmium and zinc in the acidic soil–Sauropus androgynus system

Humic acids (HA) are a popular soil additive to reduce metal availability, but they have the drawbacks of reduced effectiveness over time and a significant reduction in soil pH. An alkaline humic acid fertilizer (AHAF) combining alkaline additives with HA was developed to overcome such drawbacks. A field experiment was conducted to investigate the effects of different AHAF application rates on the physicochemical properties, bioavailability, accumulation, and translocation of Cd and Zn heavy metals in Sauropus androgynus grown in acidic soil. Based on our results, the 100AF (100% AHAF) treatment significantly increased soil pH, cation exchange capacity (CEC), and organic matter content (OM) after one year of application. Compared with the control treatment (CK), the application of different rates of AHAF resulted in a 37.1–40.3% decrease in soil exchangeable Cd fractions (Exc-Cd) and an increase in the humic acid-bound Cd fractions (HA-Cd) Fe- and Mn-oxide-bound Cd fractions (OX-Cd), and organic matter-bound Cd fractions (OM-Cd) by 9.5–64.6%, 24.8–45.1%, and 158.8–191.2%, respectively (P < 0.05). The different AHAF treatments decreased the Res-Zn, Exc-Zn, and OM-Zn fractions by 69.6–73.0%, 7.4–23.9%, and 18.1–23.2%, respectively (P < 0.05), and increased the HA-Zn fraction by 8.4–28.1%. In the control treatment, the bioconcentration factors (BCFs) for Cd and Zn in different S. androgynus plant organs were in the following order: (Cd) Leaves > Stems > Branches > Roots > Edible branches; (Zn) Roots > Stems > Leaves > Branches > Edible branches. The transfer factors (TFs) of Cd and Zn in S. androgynus were classified as follows: TF2 > TF1 > TF3 > TF4. Thus, S. androgynus stems, and roots had a strong ability to transport Cd and Zn to the leaves. Compared with CK, the 100AF treatment significantly increased the BCFs for Zn in all plant parts (except BCFedible branches). In contrast, it significantly decreased all BCFs and TFs for Cd and the TF4 for Zn, effectively reducing Cd and Zn accumulation in the edible branches of S. androgynus. Soil pH, CEC, OM, and HA-M fraction were highly and significantly negatively correlated with Cd and Zn content in edible branches (P < 0.001). Stepwise multiple linear regression analysis revealed that the soil HA-M fraction was the key contributing factor for Zn accumulation and translocation in S. androgynus. Moreover, based on our findings, the absorption, uptake, and translocation of Cd and Zn were mainly determined by metal speciation and the pH in the soil. Moreover, the competitive antagonistic mechanisms between Zn and Cd absorption also affected their accumulation in S. androgynus. Thus, AHAF can be used as a soil amendment to sustainably improve acidic soils and effectively reduce Cd and Zn accumulation in edible branches of S. androgynus.

Effects of blended NPSB fertilizer rates on selected soil properties at Banshure Kebele, in Bedele District, South Western Ethiopia

Balanced fertilizer application is an important management practice to improve soil fertility and quality in the agricultural lands. In present study, we examined the effects of nine different rates of blended NPSB fertilizer rates on soil pH, soil organic carbon (SOC), total nitrogen, available sulphur (ava.S), available boron (ava.B) and available phosphorus (ava.P) in the plowed layer (0-20 cm). The results obtained from this study indicated that, the values of soil pH obtained from all treatments are lower than that of soil pH before fertilizer application. The application of fertilizer have remarkably improved soil organic carbon (SOC) and total nitrogen (TN) values compared with soil organic carbon (SOC) and total nitrogen (TN) recorded before fertilization. Except soil total nitrogen (TN) and soil organic carbon (SOC), application of different rates of blended NPSB fertilizer were highly significantly affected the values of soil pH, available phosphorus (ava.P), available sulphur (ava.S), and available boron (ava.B). The highest values of available phosphorus (ava.P), available sulphur (ava.S), and available boron (ava.B) were obtained from the plot treated with the highest (300kg/ha) fertilizer rate, were as the lowest was recorded from the control plot. Unlike available phosphorus (ava.P), available sulphur (ava.S), and available boron (ava.B), the values of soil pH recorded after fertilizer application becomes declined as the rate of fertilizer applied to the soil is increased dramatically. Thus, these indicated that, as the rate of blended NPSB fertilizer increased soil acidity becomes increased due to the presence of soil acidifying compounds such as nitrate, sulphate and boric acid in blended form.

Morphological Growth of Soybean (Glycine max L.) Treated with Soil Application of Humic Acid under Different Cultivation Periods

The demand of organic cultivation of plants is increasing and soil application of organic fertilizer reduces the hazardous usage of inorganic fertilizer and Humic acid is an organic compound derived from plant and animal residues and microbial cells with long-term physical, chemical, and biological processes. In addition, ultivation of soybean in Kurdistan region is not in a wide value therefore, the objective of this study was to determine the impact of soil application of different rates of Humic acid as an organic fertilizer on the growth characteristic of soybean cultivated and determining the best cultivation period for soybean growth. The experiment was conducted in randomized complete block design with two factor treatments and 3 replication, the first factor was one dose soil application of four different Humic Acid rates (HAR) which were (0 (control), 2,4,6,8 g/L) and two cultivation period (CP) which were cultivation Period 1 (CP1) on 15 May 2022 and cultivation Period 2 (CP2) on 1st of June 2022. Observations were made against the growth parameters of plant height number of branches, leaf area, root length, shoot fresh weight and shoot dry weight. The effect of soil application of humic acid rates (HAR) was highly significant on the plant height and root length and significant on the No. of branches, shoot fresh and dry weight. While, cultivation period insignificantly affected the growth parameter except for leaf area. was significant. The maximum plant height, number of branches, leaf area, root length, shoot fresh and dry weight were observed with soil application of 8 g/L of humic acid which were (82.83 (cm), 23.33, 8815 (mm2), 68.83 (cm), 503.33 (g) and 190.00 (g) respectively. The highest plant height (72 cm), number of branches (18.87), leaf area (7714 mm2), root length (57.13 g), shoot fresh (263.67 g) and dry weight (102.93 g) were observed when the planted cultivated in 1st period (CP1) compared to CP2.

EFFECT OF COMPOST PRODUCED WITH COW DUNG ON THE EARLY GROWTH OF Adansonia Digitata L.

This experiment was carried out to determine the effect of different levels of compost produced with Cow dung on the early growth performance of Adansonia digitata. A. digitata seeds were planted in a seed box and transplanted into poly pots after germination with the application of compost produced with Cow dung at a rate of 1kg, 2kg and 3kg per treatment and a control experiment. This experiment was carried out in a Completely Randomized Block Design. Data on plant height, number of leaves, leave area, leave width and collar diameter were recorded. The data were collected weekly for eleven weeks starting from the second week after planting. The data collected were subjected to statistical analysis using ANOVA. Result of the experiment revealed the highest mean height (137.63±19.46) was obtained in the control experiment, highest number of leaves (17.67±2.52) was recorded at treatment 4 (3kg), The widest leaf area was recorded at treatment 3 (2kg) (77.98±2.45) and the highest mean collar diameter was recorded is obtained in the control experiment (7.25±2.05). It is deduced that, the compost from cow-dung indicates no significant improvement in the early growth performance of A. digitata; also, different rates of application have different influence on the growth of the plant. In order to obtain optimum growth and yield of A. digitata, proper soil management techniques (such as application of organic manure) should be adopted and to maintain stable soil fertility; application of compost is advisable.

Effect of Different Rate and Time of Application of Slag based Gypsum on Nutrient Use Efficiency, Quality and Yield of Groundnut

Background: Slag based gypsum (SBG) is a value-added product of iron and steel industry. Application of gypsum as source of calcium and sulphur for groundnut cultivation is common practice and mainly applied during peg initiation stage of groundnut. However, its effect is mainly influenced by the type of soil and dissolution of gypsum, which facilitates the yield and quality of groundnut. Hence, field experiments were conducted to know the effect of application of different rates of SBG as basal and split application on soil properties, yield, quality, nutrient use and uptake efficiency of groundnut in acidic soil. Methods: This study contains of seven treatments which includes recommended dose of fertilizer (RDF) with three levels of SBG (375, 500 and 625 kg ha-1) was applied as basal and split and 500 kg natural gypsum (NG) ha-1 was applied as basal dose according to package of practice (POP) of University of Agricultural Sciences, Bangalore by using randomly complete block design (RCBD) at Agricultural Research Station, Balajigapade during kharif 2018 and 2019. Result: The pooled data of two field experiments on groundnut revealed that application of RDF + 625 kg SBG ha-1 as 50% at sowing + 50% at peg initiation stage recorded higher pod (28.01 q ha-1), haulm (54.46 q ha-1), kernel (20.59 q ha-1), protein (89.70 q ha-1) and oil (7.06 q ha-1) yield when compared to other treatments. There was an increase in pod, haulm and oil yield of groundnut by 11.62, 20.59 and 17.99%, respectively with the split application of 625 kg SBG ha-1 (50% at sowing + 50% at 30 DAS) over NG applied treatments. Split application of SBG significantly increased the availability of nutrients in post harvest soils than basal application. Significantly higher S and Ca nutrient use efficiency (33.98 and 28.93 kg produce/kg S and Ca utilized, respectively) and uptake efficiency (0.39 and 1.29 kg kg-1, respectively) was recorded with the split application of SBG @ 375 kg ha-1.

Evaluation of Nitrogen and Phosphorus Responses on Yield, Quality and Economic Advantage of Winter Wheat (Triticum aestivum, L.) under Four Different Agro-Climatic Zones in Afghanistan

The response of winter wheat (Triticum aestivum L.) to the application of different rates of nitrogen (N) and phosphorus (P) on different agro-climatic zones (ACZs) has not been well studied in Afghanistan. The objectives of this study were to (1) determine the impact of soil and climate on the responses of wheat to N and P fertilization, (2) quantify the specific N and P response of winter wheat for different ACZs, and (3) determine the economical application rates of N and P for farmers for each considered ACZs. This paper evaluates the effects of nitrogen levels (NL) at 35.28, 65, 95, and 120 kg N ha−1 and phosphorus levels (PL) at 0, 50, 70, and 90 kg P2O5 ha−1, respectively, in four locations (L) for two growing seasons (GS), on both yield and quality characteristics of winter wheat. Soil pH was the main environmental parameter affecting straw yield (SY), grain yield (GY), protein content (PC), and protein yield (PY). Winter wheat SY, GY, PC, and PY increased significantly (p &lt; 0.05) with PL rates up to 50 kg P2O5 ha−1 and with NL rates up to 120 kg N ha−1. NL was the most important parameter in determining PC, thus showing potential for further improvement in N management. The highest marginal rate of return was used as an index for the farmers to accept site-specific N and P fertilizer recommendations.

Alternate of Manual Weeding Tools: A Research into an Automatic Weeding Control Strategies Enabled by Embedded Systems

A key enabling factor for treating individualized weeds in the crops is the Automatic Weeding Control device (AWCd) as it is being capable of finding and distinguishing weeds in the field. The non-herbicide approaches used to manage weeds are a component of the personalized treatment of weed crops. In this study, mechanical weed control techniques are investigated as an alternative. In this study, three specifications—a cutting mechanism, a head-surface tilling (tines), and a foot-surface tilling (arrow hoe)—are taken into account. With different rates of application to herbicide-resistant, these processes were estimated in a controlled field and the efficacy of the implementation is estimated by using the demographic analysis and also, the importance of early interface has also been highlighted. For all the weeds accounted in this research, Automatic weeding control was found to be very effective thus ended up in overall survival probability.

Study of the effect of the combined fungicide Abacus Ultra on the population structure of the wheat leaf rust pathogen

Aim. To study the variability of the intrapopulation structure of the causative agent of wheat leaf rust (Puccinia triticina Erikss.) on the basis of pathogenicity under the influence of the combined fungicide Abacus Ultra, SE.Material and Methods. The studies were carried out in the greenhouse complex of the Federal Research Center of Biological Plant Protection on the winter wheat variety Krasnodarskaya 99 which is susceptible to leaf rust. The material studied was the combined fungicide Abacus Ultra, SE with application rates of 0.75; 1.0; 1.25; 1.5; 1.75 l/ha. The work was carried out according to generally accepted methods.Results. The influence of the impact of different rates of application of the fungicide Abacus Ultra, SE on the average virulence of the P. triticina population was established, this indicator varying from 40.0% (control [without treatment]) to 19.5% (fungicide application rate 1.75 l/ha). As a result of the analysis of the phenotypic composition of the population, 5 phenotypes were identified. A decrease in the viability of spores of the fungus P. triticina with an increase in the rate of application of the fungicide was established, this indicator varying from 69.1% (0.75 l/ha) to 29.2% (1.75 l/ha). A decrease in the aggressiveness of the population of the causative agent of leaf rust with an increase in the rate of application of the drug was established. The biological effectiveness of the fungicide Abacus Ultra, SE against the pathogen was 95.3–97.8% at the recommended application rate of 1.0–1.5 l/ha.Conclusion. The study showed that the population of the leaf rust pathogen treated with the chemical fungicide Abacus Ultra, SE is characterised by a change in structure in terms of aggressiveness and virulence, while the sensitivity remains high due to the combination of the active substances pyraclostrobin and epoxiconazole with a different mechanism of action in the preparation.

Effect of Combined Application of Vermicompost and NPS Fertilizer Rates on Growth, Yield and Yield Components of Maize (Zea mays L.) at Toke Kutaye District, Ethiopia

Maize is one of the major and important cereal crops in Western Shewa Zone, particularly, in the Toke Kutaye district. However, the yield of the crop is low mainly due to the low fertility status of the soils. Integrated use of vermicompost and NPS fertilizers is indispensable to improve this condition of the soil. In this context, a study was conducted in 2019/2020 to assess the effect of the combined use of vermicompost and NPS fertilizer on yield and yield components of maize. To achieve this objective field experiment was laid out in a randomized complete block design and replicated three times. The results of this study revealed that the current scenarios of maize production in Toke Kutaye district call for appropriate ways of adding nutrients to the soil to obtain optimum maize productivity. In response to this, the combined application of different rates of vermicompost and NPS fertilizer to soil significantly affected most parameters used for this investigation such as plant height, leaf number, leaf length, leaf area, stand count, ear length, and a number of ears per plant, thousand-grain weight, total above-ground dry biomass and grain yield of maize. Moreover, the combined form of NPS blended fertilizer and vermicompost was applied and the result revealed that the sole application of recommended NPS fertilizer and vermicompost increased maize yield by 52.27 and 55.72% over control treatments, respectively. Besides this, the combined use of vermicompost and NPS fertilizer by the rating of half of the recommended rate of both fertilizers increased maize yield by 60.05% over the control treatment. This indicates that the best option for soil fertility management is integrated soil fertility management that involves the combined use of vermicompost and NPS fertilizers as nutrient sources than the strategy of using organic or inorganic amendments alone. Then, it could be concluded that the use of blended NPS fertilizer at 50 kg ha-1with supplemental vermicompost at 5 t ha-1 to Jibat variety is the realistic approach to address the problem of low productivity of maize in the study area and other similar agroecology. Based on the findings and conclusions of this study it can be recommended that farmers in the study area should, therefore, be advised to use this variety and combined use of vermicompost and NPS fertilizer at a rate of 5 t ha-1 VC +50 kg ha-1 NPS for sustainable maize crop production tentatively. Nevertheless, further studies are needed to recommend agronomical optimum and to measure the long-term effects of the integrated soil fertility management techniques in more seasons, soil types and crop varieties before giving a conclusive recommendation.

Effects of Three Different Rates of Application of Cattle Dung on the Growth and Quality of Two Traditional Leafy Vegetables (Amaranthus Cruentus and Corchorus Olitorius)

Traditional leafy vegetables have been noted to supply abundant amounts of minerals and to some extent calories and proteins which are vital to the alleviation of problems of malnutrition in developing countries. An experiment was conducted to study the effects of three different rates of application of cattle dung on growth parameters, proximate and mineral composition, weight loss and shelf life of Amaranthus cruentus and Corchorus olitorius. The treatments were cattle dung manure at rates of 0, 0.5. 0.8 and 1.1 t/ha. Application of 1.1 t/ha in Amaranthus cruentus resulted in the highest plant height on the 20th day after transplanting. The 0.8 t/ha rate of application gave the highest number of leaves and shoots of Amaranthus cruentus. Higher rates of application produced bigger stem girths which varied significantly from those without manure application. On the effects of the different rates of application on Corchorus olitorius, the results showed that, generally, there was no significant difference (P &gt; 0.05) from those without manure application. Increased rates of application resulted in a decline in the growth parameters. The results on shelf life for both Amaranthus cruentus and Corchorus olitorius showed that both wilted and dried on the 24th hour and 48th hour after harvesting respectively. In conclusion, the study showed that increased application of cattle dung produced positive outcomes on the growth parameters of Amaranthus cruentus.

Integrated Effect of Organic and Inorganic Manuring on Crop Yield and Soil Nutrient Balance in the On-going Century-old Permanent Manurial Experiment

Aim: The present study reports the results of continuous application of different rates of N, P and K and organic manure to a Maize-Sunflower cropping system on the changes in soil available nutrients status after harvest of 172th crop of maize.&#x0D; Materials and Methods: We studied the long-term effect of organic and inorganic manuring on crop yield and soil nutrient management under Maize–Sunflower cropping system in 112 years old Permanent Manurial Experiment Field. Significant build-up in soil fertility in terms of alkaline KMnO4-N, Olsen-P, NH4OAc-K, K2Cr2O7–C and CaCl2-S as well as DTPA-Fe, Mn, Cu, Zn were assessed under eight treatments consist of Unfertilized Control, NP, NP, NPK (Chemical Fertilizer Alone), FYM (N Equivalent Basis), FYM (Every Year), Poultry Manure and NPK+FYM.&#x0D; ResultS and Discussion: Recorded data from 2008 shows that continuous application as 100%NPK+FYM @12.5 t ha-1 achieved highest grain yield (hybrid maize CO 6), soil organic carbon, available nitrogen, available potassium, available sulphur and micronutrients content. Highest P recorded in poultry manure on nitrogen equivalent basis than INM irrespective of the crops. Inorganic fertilizer application alone resulted in a pH of &gt;8.0, whereas fertilizer and manure application as well as manure application alone resulted in a pH of &lt; 8.0 in soil. The increase in available S in INM, NPK alone might be due to single super phosphate (SSP) and FYM which contained about 12 and 0.74 % of S, respectively. Thus, considering soil-quality conservation and crop yield, 112 years of study indicated that combined application of NPK and organic manure is a better nutrient-management option in this irrigated maize sunflower cropping system.&#x0D; Conclusion: These results conclude that for better crop yield and soil quality, integrated usage of organic and inorganic nutrient should be advocated in the Maize-Sunflower cropping system under Alfisol.

Protection of soybeans against weeds with a two-component herbicide

The article presents information on the effectiveness of a two-component herbicide on soybean crops. The effectiveness of its use at different rates of application and application both with and without adjuvants, as well as species sensitivity to weeds have been studied. The variants of chemical weeding, in which the maximum suppression of weeds was achieved, providing a high yield of soybean grain, were determined.

Influence of different rates of application of herbicide Euro-Lightning on weed infestation and sunflower yield in the stationary crop rotation UNPO “Povolzhye”

The results of various norms of application of the herbicide Euro-Lightning (1,2, 1,0, and 0,8 l/ha) in sunflower hybrid crops “Volcano” are presented. Field small-scale experiments were laid in the conditions of stationary crop rotation of the UNPO “Volga region” of the Saratov State Agrarian University. Stepnoye of the Engels district of the Saratov region. The size of the plots was 25 m2, the location of the plots was randomized, the repetition was fourfold, the processing was single. Method of application: spraying of vegetative plants. In sunflower crops, 7 species of weeds belonging to 6 families were noted: Echinochloa crusgalli (L.) Beauv., Setaria pumila (Poir.) Schult., Chenopodium album L., Amaranthus retroflexus L., Fallopia convolvulus (L.) A. Löve, Convolvulus arvensis L., Lactuca tatarica (L.) C.A. Mey. The best result in the fight against weeds and an increase in sunflower yield was shown by the herbicide Euro-Lightning at a rate of 1.2 l/ha: biological efficiency, taking into account the total contamination, was 98.1 -100%, crop yield increased by 31.3% compared to the control.

Improvement of Soil Nutrient and Yield of Maize Through the Application of Different Rates of Sawdust - Piggery Compost Fortified With Urea

Fortification of compost with inorganic fertilizer is necessary to compliment for some deficient nutrient in organic manure to improve soil fertility and crop yield. This experiment was carried out at Ambrose Alli University Teaching and Research Farm, Ekpoma, Nigeria and it was fitted in a Randomized Complete Block Design (RCBD) with seven treatments replicated thrice. The treatments were; Control, 2 tonnes of saw dust piggery compost + 75Kg/ha of urea, 4 tonnes of sawdust piggery compost + 75kg of urea, 6 tonnes of sawdust piggery compost + 75kg of urea (75kg Urea +6 SPC), 8 and 10 tonnes of compost, 150kg/ha of urea. Data collected were analysed using ANOVA and LSD was used to separate means. It was observed from the initial soil test that the soil nutrients status was below critical levels and this necessitate the application of the fertilizer to improve the fertility status of the soil. The application of 75kg Urea + 6 SPC significantly (p≤0.05) increased the soil nutrient status compared to other treatments. The growth, cobs weight, dry matter and grain yield of maize were significantly (p≤0.05) higher with application of 75kg Urea +6 SPC compared to other treatments. Also, the nutrient uptake of maize was significantly (p≤0.05) higher with application of 75kg Urea + 6 SPC. In conclusion, the application of 75kg Urea +6 SPC significantly (p≤0.05) increased the soil nutrient status, growth and the yield of maize.

Simulating phosphorus leaching from two agricultural soils as affected by different rates of phosphorus application based on the geochemical model PHREEQC.

Phosphorus (P) leaching from agricultural soils, in consequence of long-term utilization of P fertilizers, decreases the water quality and leads to eutrophication. The effect of monopotassium phosphate (MKP) at the rates of 0, 50, 200, 400, and 800mg P kg-1 on P and certain cations leaching from two agricultural soils (loam and sandy loam soils) was investigated in a laboratory study. Soil treatments were packed in columns with 5cm in diameter, up to 10cm. Soil columns were leached using distilled water solution for 20 pore volumes, and the leachates were analyzed for pH, electrical conductivity (EC), calcium (Ca), sodium (Na), potassium (K), and P. To simulate the concentrations of K and P in leachates, the PHREEQC model was utilized. In addition, the P vertical distribution in different depths of the soil columns after the leaching experiment was investigated using Olsen-extractable P (Olsen-P). Generally, as the MKP rates increased, the mean(mean of 20 pore volumes) value of pH and Ca concentration in leachates decreased, but the mean value of EC, Na, and K concentrations in leachates increased. In early pore volumes, the P concentration in all treatments begins to rise, then begins to fall. The application of different rates of MKP fertilizer increased the cumulative amount of P leached in both studied soils. Significant relations were obtained for the rates of MKP application and the cumulative amount of P leached. Overall, the model did a good job of simulating K and P concentrations in leachates, as well as the trend of K and P leaching. In both treated soils with increasing of fertilizer rates, the Olsen-P status in all depths increased, and the P content increased with depth. The Olsen-P contents before the leaching experiment for each treatmentwere predicted, and power equations significantly described its relation with mean P concentration in leachates. Higher application rates of MKP (400 and 800mg P kg-1) resulted in much higher P concentrations in leachates than the threshold value (0.1mgl-1), and these rates should not be used in agricultural soils, whereas applying 50mg P kg-1 to agricultural soil could be a reasonable rate for preventing P losses.

Application of Different Rates and Frequencies of Rejuvenator for the Treatments of Brown Bast Syndrome on Hevea brasiliensis

Background: Brown bast is one of the most serious threats to natural rubber production. It is estimated that brown bast leads to an approximately 15-20% decrease in latex yield production. There is currently no effective method to control this problem and an effort to overcome this problem is in progress by the natural rubber producing countries. Methods: This study evaluated the effect and the most suitable rate and frequency of Rejuvenator application to cure brown bast (latex dryness) and improve latex yield. The Rejuvenator treatment was applied to the selected tree with two different treatment frequencies (every 3 days and every 6 days) and three different Rejuvenator concentrations (5 g/L, 10 g/L and 5 g/L). The Rejuvenator was applied 5 times. Data on latex yield and brown bast cure were then recorded 1 month after the application of the last treatment. The treatments used were T1: No Rejuvenator, T2: 5 g/L of Rejuvenator, T3: 10 g/L of Rejuvenator, T4: 15 g/L of Rejuvenator. Result: Of all the treatment used, T3 (10 g/L) resulted in higher production of latex yield and Hevea bark nutrient concentration (g/t/t) than control. It also gave the highest nutrient content in the bark tissue. The findings of this study reveal that the optimum concentration and frequency of Rejuvenator application were established at 10 g/L every 6 days. More so, the findings explain that inadequate nutrients can be attributed to the brown bast syndrome in rubber plantation which can be prevented with the use of a rejuvenator to the tree’s bark.

Balanced fertilization increases wheat yield response on different soils and agroecological zones in Ethiopia

AbstractThe response of wheat to the application of different rates of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) under balanced fertilization on different soil types and agroecologies has not been well studied in Ethiopia. Therefore, the objectives of this study were to (1) determine soil-specific responses of wheat to N, P, K, and S under balanced fertilization; (2) quantify agroecology-specific N, P, K, and S response of wheat under balanced fertilization; and (3) determine nutrient use efficiency of wheat on different soil types under balanced fertilization. Trials were conducted on farmers’ fields across 24 locations covering 4 soil types and 5 agroecological zones (AEZs) from 2013 to 2017. The mean grain yields of wheat significantly varied with applied N and P fertilizer rates with soil types and AEZs. With balanced application of other nutrients, the optimum N rates for wheat were 138 kg N ha−1on Cambisols and Luvisols, 92 kg N ha−1on Vertisols, and 176 kg N ha−1on Nitisols, while the optimum P rate was 20 kg P ha−1on Cambisols and Vertisols. The nutrient dose–response curve did not reveal consistent pattern for K and S applications on all soil types. The agronomic efficiency of wheat decreased with increasing rates N and P on all soil types. The highest agronomic efficiency of N (15.8 kg grain kg−1applied N) was recorded with application of 92 kg N ha−1on Vertisols, while the highest agronomic efficiency of P (49 kg grain kg−1applied P) was achieved with application of 10 kg P ha−1on Cambisols. We conclude that applications of 92–138 kg N ha−1, 20 kg P ha−1, 18 kg K ha−1, and 10 kg S ha−1under balanced application of zinc and boron could be recommended depending on soil type for wheat production in the study areas.

Economically Optimal Rates and Nutrients Use Efficiency Indices of Maize to the Application of Different Rates of Nutrients in Central Rift Valley of Ethiopia

The use of balanced fertilizers in adequate amount is very important to increase crop productivity and production in Ethiopia. The study was executed to quantify maize (Zea mays L.) grain yield response to different rates of nitrogen (N), phosphorus (P), potassium (K) and sulfur (S) under balanced fertilization of other nutrients. On farm trials were conducted at seven sites on 8 farmers’ fields in Negele Arsi districts, west Arsi zone of Oromia region for three consecutive cropping seasons (2014-2016). Six rates of N, P, S and eight rates of K treatments established separately for each nutrient were laid out in randomized complete block (RCB) design with three replicates per farm. Nutrient response function modelling showed that 184, 20 and 80 kg•ha−1 were the agronomic optimum rate for N, P, and K, respectively. Mean agronomic efficiency (AE) of N, P and K were recorded at the lower rates of these nutrients, application of 46, 10 and 20 kg•ha−1 N, P and K resulted in 19.1, 61.0, and 24 kg additional grain yield•kg−1 N, P and K, respectively. Also, the mean partial factor productivity (PFP) of N, P and K were 77.6, 370 and 158 kg additional grain•kg−1 applied N, P and K respectively. Economically optimal rate (EOR) of N, P and K were 48 - 114 kg•ha−1 N with CP 8 - 3.5, 12 - 20 kg•ha−1 P with CP 18 - 4.5 and 32 - 53 kg•ha−1 K with CP 8-4, from these rates net returns of US$487.23 - 143.30, US$698.16 - 498.3 and US$359.31 - 193.63 could be obtained respectively. To conclude, application of 84, 12 and 40 kg•ha−1 N, P and K could be recommended for the production of maize.