American Journal of Agricultural Research

  • Nitrogen Nutrition, Yield, and Quality of Cotton under Varying Nitrogen Application Timings and Planting Dates

    Nitrogen (N) management may need to be different for cotton planted at different dates. The objective of this research was to determine the optimal N application timing for cotton under different planting dates. A field trial was conducted on the University of Tennessee West Tennessee Research and Education Center at Jackson, TN in 2011 and 2012 in a split plot randomized complete block design with four replicates. Three cotton planting dates of early planting, standard planting, and late planting and four N application timings of pre-plant, at-planting, early side-dress, and late side-dress were assigned to the whole plots and subplots, respectively. Although the interactions of planting date by N application timing, year by N application timing, and year by planting date were significant on leaf N at early bloom and late bloom; cotton plants received adequate N nutrition for optimal yield under different N application timings and varying planting dates in both years. No significant difference in lint yield was observed among the four N application timings regardless of planting date in 2011 that was wet in the early season but dry in the late season. In 2012 that was dry in the early season but wet in the late season, however, lint yield was higher with late side-dress of N than pre-plant at standard planting; the yield did not differ among the four N application timings at early planting or late planting. Higher fiber micronaire but lower fiber strength was obtained under early planting and standard planting than late planting. In 2011, the length and uniformity of fiber were not affected by the planting date. In 2012, however, the length and uniformity of fiber were greater at late planting than early planting and standard planting. The fiber length and fiber uniformity were greater with late side-dress of N than…

  • Development status and trend of high efficiency grain air-and-screen cleaning device

    The cleaning device in modern agricultural equipment is an important part of the reference of the grain combine harvester. The loss rate of the grain and other factors are directly affected by the cleaning device. In this paper, the development status of the current cleaning equipment and the research and analysis are described in three aspects: the distribution of the airflow field in the cleaning device, the movement law of the exudate, and the research on the centrifugal fan. The loss rate and the impurity ratio of the grain harvest are reduced. Objectives, reviewed the research status and trends of domestic and foreign grain combine harvester cleaning equipment, and put forward new ideas for the future development prospects and prospects of grain combine harvester, and provide reference for improving the research and design of grain harvester cleaning equipment. experiments.

  • Soil Nutrient Levels after Corn Harvest under NPSFe Biofertilizer and NPKZn Briquettes

    Interest in the use of alternate fertilizers has increased in recent years for improving crop nutrition and soil health. The efficacy of these fertilizers on corn (Zea mays L.) production has not been well documented. Alternate fertilizers organically enhanced NPSFe biofertilizer (NPSFe) manufactured from sterilized organic additives extracted from municipal wastewater biosolids and NPKZn briquettes (briquettes) produced by compacting commercially available solid fertilizers into a super-granule between 1-3 grams were evaluated for nutrient concentrations in the soil relative to common fertilizers ammonium sulfate (+P+K) and urea (+P+K) at Jackson and Grand Junction, TN from 2011 to 2013. NPSFe, the briquettes, ammonium sulfate, and urea and four N application rates of 0, 85, 128/170, and 170/255 kg ha-1 were assigned to the main and sub plots, respectively, in a split plot randomized complete block design with four replicates. Soil at a 0-15 cm depth was analyzed for Bray P, NO3–N, NH4+-N, SO42–S, and organic C concentrations after corn harvest. The briquettes produced lower soil NO3–N concentrations than the other fertilizers particularly under wet soil conditions. NPSFe sometimes had higher post-harvest soil NH4+-N than the briquettes and ammonium sulfate. NPSFe sometimes tended to be higher than the other fertilizers in post-harvest soil P concentrations after corn harvest, thus the P provided by NPSFe may be less available than TSP. NPSFe and ammonium sulfate both increased post-harvest soil SO42–S levels compared to the briquettes and urea, particularly at higher application rates. NPSFe had greater soil organic C level than the other fertilizers. In conclusion, NPSFe consistently increases soil organic C level, particularly at the higher N rates, within three years of experimentation, which may promote microbial activities and health of the soil.

  • Corn Mineral Nutrition Responses to NPSFe Biofertilizer and NPKZn Briquettes

    Alternative fertilizers have been increasingly developed during recent years in order to improve crop nutrition. The efficacy of these fertilizers on corn (Zea mays L.) production has not been well examined. Alternative fertilizers of organically enhanced NPSFe biofertilizer (NPSFe) manufactured from sterilized organic additives extracted from municipal wastewater biosolids and NPKZn briquettes (briquettes) produced by compacting commercially available solid fertilizers into a super-granule between 1-3 grams were evaluated for nutrient concentrations in plant biomass and grain of corn compared to commonly used N fertilizers ammonium sulfate and urea at Jackson and Grand Junction, TN during 2011-2013. NPSFe, the briquettes, ammonium sulfate, and urea and four N application rates of 0, 85, 128/170, and 170/255 kg ha-1 were assigned to the main and sub plots, respectively, in a split plot randomized complete block design with four replicates. Aboveground plant biomass at the silking growth stage (R1) and physiological maturity stage (R6) and grain at harvest were analyzed for N, P, K, S, Fe, and Zn concentrations. NPSFe resulted in similar or lower plant N concentrations relative to the conventional fertilizers ammonium sulfate and urea. The briquettes performed equally or better in terms of plant N concentrations compared to ammonium sulfate and urea. In excessive spring precipitation, the briquettes had higher biomass N concentrations at R1. NPSFe tended to have lower P concentrations in plant biomass at R1 and R6. The briquettes had similar or higher plant P levels relative to ammonium sulfate and urea. Both NPSFe and ammonium sulfate increased S concentrations in plant biomass compared to the briquettes and urea. In conclusion, the briquettes do not consistently improve corn N, P, K, and Zn nutrition compared to the conventional fertilizers ammonium sulfate and urea. NPSFe sometimes seems to reduce corn N and P nutrition but increase Zn nutrition relative to…

  • Research on screening performance of double layer vibrating screen for soybean harvester based on discrete element method

    In order to improve the screening effect of grain combine harvester, it is necessary to study the influence of different screening parameters on screening performance.In this paper, discrete element method was used to simulate the screening process of soybean and short stems by selecting different screening parameters, and dynamic screening efficiency and the number of short stems under screening were introduced as evaluation criteria.The results show that under certain other conditions, the vibration frequency, amplitude and direction angle have significant influence on the screening performance, while the inclination angle of the upper screen has little influence on the screening performance. With the increase of vibration frequency, amplitude and direction angle, screening efficiency increased first and then decreased, while the number of short stalks under screening increased first and then decreased. Considering the screening efficiency and the number of short stalks under the screening, it is concluded that the screening performance is better when the amplitude is 25 mm, the vibration frequency is 4 Hz, the vibration direction angle is 25 degrees and the upper screening angle is 3 degrees. The simulation results are verified by field experiments, and the simulation results meet the requirements of field experiments.

  • Development of Light Sensors to Measure Defoliation

    Sensors have become valuable tools in agriculture when decisions regarding inputs require precision and speed. For example, factors in estimating defoliation in row crops, such as intensive labor and, in particular, subjectivity, are greatly reduced with the use of sensors that can remove these limitations and biases. Estimates of defoliation are almost always overestimated due to human error and biased, unconscious efforts to locate injury. To address these issues, the accuracy and preciseness of a light-based sensor to detect defoliation was tested by measuring simulated levels of defoliation (0-100%) on paper “leaves” at seven light intensities. Results indicated that higher lux values were detected through thinner paper (filter paper) than through thicker paper (cardstock), demonstrating that leaf thickness could potentially affect accuracy of the light-sensor system. Despite some light penetrating the thinner paper with simulated defoliation levels, the two light sensors tested yielded accurate and precise predictions of defoliation (R2 > 0.95). This light-sensor approach could potentially be used in the field to report real-time measurements of defoliation in row crops, such as soybeans, or in other plant-based systems where losses of leaf area require monitoring in order to prevent economic injury.

  • The growth and nutrient utilization of Clarias gariepinus (Burchell 1822) fed Parkia biglobosa meal based diet

    The study investigated the growth and nutrient utilization of Clarias gariepinus fingerlings fed five iso-nitrogenus diets, containing fermented locust bean meal, at varying inclusion level (0%, 10%, 20%, 30%, 40%, 50%) as replacement for fishmeal. Eight weeks feeding trial was conducted using Clarias gariepinus fingerlings which were randomly distributed into 12 bowls at a stocking rate of 20 fish per bowl, in replicates per treatment. The experimental design was completely randomized. The fish were fed at 5% body weight, twice daily. Six isonitrogenous (35% crude protein) diets containing fermented locust beans meal at varying replacement level for fish meal designated as diet A0, B10, C20, D30, E40 and F50 were formulated and fed to the fish. All the experimental fish fed the various treatments showed increase in weight, carcass crude protein and lipid content, compared to the initial value indicating positive contribution of the various diets to growth of the fish. The results obtained indicated there was no significant difference (P>0.05) in the mean weight gain, percentage weight gain. Specific growth rate, food conversion ratio and protein efficiency ratio among the fish fed the various diets. The highest weight gain was recorded in the fish fed the control diet (2.47g) while the least was recorded for the fish fed the B20 diet (2.18g). This study revealed that locust bean seed if processed, as in fermentation, could replace fishmeal up to 50% level in the diet of C. fish. This level of inclusion would be a significant replacement for the expensive fishmeal in feed manufacturing.

  • AN ECONOMIC ANALYSIS ON PRODUCTION FUNCTION OF MANGO CULTIVATION IN THENI DISTRICT, TAMILNADU

    Fruits and vegetables are considered to be the protective food because these help us to develop a defence mechanism in our body. Mango (Mangifera indica), which is the king of fruits for over 4000 years, is also our national fruit. There are more than thousand mango varieties in India. At present, India is one of the largest producers of mango, however, only about 30 varieties are grown on commercial scale in different states. Important mango varieties are cultivated in different states of India in which Tamilnadu cultivates the varieties like Banganpalli, Bangalora, Neelum, Rumani, and Mulgoa. More than 50 per cent of world mango production is contributed by India, but unfortunately mango productivity in the country is declining over the years. The productivity of Mango in Tamilnadu State was found to be low when compared to the National Average Productivity. The reason for this may the farmers are facing problems in processing and getting market information. The extension service providers also lack information on changing market needs and are not able to advise the producers appropriately. Hence this study is important and the results obtained will be utilized by the policy makers and the planners in horticulture and agriculture for further development of these sectors. An Economic Analysis Production Function of Mango Cultivation in Theni district.

  • Effects of different fertilizers on growth, yield and root knot nematode Meloidogyne spp in Okra Abelmoschus esculentus under field condition in Summer Season in Chitwan, Nepal

    An experiment was carried out at Agriculture and Forestry University, horticulture farm to determine the effects of different fertilizers on root knot nematode and yield on Okra (var. Arka Anamika) at summer season in inner terai region of Chitwan, Nepal. The treatment was carried out in the completely randomized block design (RCBD) with 7 treatments replicated 3 times. The treatment included: goat manure, sesame seed cake, mustard seed cake, poultry manure, furacron, vermicompost plus untreated control including only chemical fertilizer (NPK). All treatments were added to provide the sufficient amount of Nitrogen required for the crop as recommended by Nepal Agriculture Research Council. Remaining amount of required Phosphorous and potassium was supplied by adding Single Super Phosphate and Muriate of potash respectively. The germination percentage was found significantly superior in Furacron (93.33%) and followed by goat manure (92.67%), vermicompost (86.67%), sesame (til) seed cake (82.67%), mustard oilcake (81.67%), control i.e. NPK (76.67%) and poultry manure (61%). Similarly, In terms of number of galls , furacron (3.43) was found the most effective followed by goat manure (5.60), Poultry Manure (6.63), Mustard Seed Cake (8.47), Sesame cake (9.07), vermicompost (16.60) and control (21.96). In terms of yield, poultry manure (20mt/ha) was found superior followed by vermicompost (17.38mt/ha), goat manure (16.72 mt/ha), sesame (til) seed cake (16.62mt/ha), furacron (14.61 mt/ha), mustard oilcake (12.97 mt/ha) and control (10.51mt/ha). The highest net profit was found in case of Poultry manure while the lowest incremental cost benefit ratio was obtained in Furacron and followed by Goat Manure, Poultry manure, Vermicompost, Sesame (til) seed cake and Mustard seed cake. The highest yield (20t/ha) and nematode control was obtained in Poultry manure which is at par with Furacron treatment. This experiments suggests the use of Furacron or poultry manure will provide more economic return and also decreases the…

  • STUDY OF WHEAT FIELD WEEDS IN BIRATNAGAR, EASTERN NEPAL

    Triticum aestivum L. (Bread Wheat) is a graminoid species of plant in the family true grasses, with a self-supporting growth habit. It is second staple food for the people living in Nepal. Total 45 weed species were collected from wheat field belonging to 19 families and 39 genera. Triticum aestivum L. is greatly affected by different weeds. Most of the weeds can be used as fodder.