Current Issue : July - September Volume : 2017 Issue Number : 3 Articles : 5 Articles
Artificial compaction is one of the most dangerous forms of degradation of\nagricultural soil. Recognized as a phenomenon with multiple negative effects in terms of\nenvironment and agricultural production, soil compaction is strongly influenced by the size of\nexternal load, soil moisture, size and shape of footprint area, soil type and number of passes.\nKnowledge of soil behavior under compressive loads is important in order to prevent or\nminimize soil compaction. In this paper were developed, by means of the Finite Element\nMethod, various models of soil behavior during the artificial compaction produced by the\nwheel of an agricultural trailer. Simulations were performed on two types of soil (cohesive and\nnon-cohesive) with known characteristics. By applying two loads (4.5 kN and 21 kN) in\nfootprints of different sizes, were obtained the models of the distributions of stresses occuring\nin the two types of soil. Simulation results showed that soil stresses increase with increasing\nwheel load and vary with soil type....
The world�s growing demand for food can be met by agricultural technology. Use of artificial light to supplement natural sunlight in\ngreenhouse cultivation is one of the most common techniques to increase greenhouse production of food crops. However, artificial\nlight requires significant electrical energy,which increases the cost of greenhouse production and can reduce profit. This paper models\nthe increments to greenhouse productivity aswell as the increases in cost from supplemental electric lighting, in a situation where\nthe greenhouse is one of the elements of a smart grid, a system where the electric energy market is dynamic and prices vary over\ntime.We used our models to calculate the optimum values for supplemental light and the required electrical energy for HPS lamps\nin the greenhouse environment, using cherry tomato cultivation as a case study crop.We considered two optimization techniques:\niterative search (IS) and genetic algorithm (GA). The two approaches produced similar results, although the GA method was much\nfaster. Both approaches verify the advantages of using optimal supplemental light in terms of increasing production and hence profit....
Monitoring soil and crop condition is vital for the sustainable management of agricultural\nsystems. Often, land management decision-making requires rapid assessment of conditions, which\nis difficult if samples need to be taken and sent elsewhere for analysis. In recent years, advances\nin field-based spectroscopy have led to improvements in real-time monitoring; however, the cost\nof equipment and user training still makes it inaccessible for most land managers. At the James\nHutton Institute, we have developed a low-cost visible wavelength hyperspectral device intended to\nprovide rapid field-based assessment of soil and plant conditions. This device has been tested at the\nInstitute�s research farm at Balruddery, linking field observations with existing sample analysis and\ncrop type information. We show that it is possible to rapidly and easily acquire spectral information\nthat enables site characteristics to be estimated. Improvements to the sensor and its potential uses\nare discussed....
Round-bale silage harvesting and processing methods were assessed to evaluate\noverwintering ability and dry matter (DM) yield, fermentation quality and palatability of\noverwintered dwarf Napiergrass (Pennisetum purpureum Schumach) in the two years following\nestablishment in Nagasaki, Japan, in May 2013 using rooted tillers with a density of 2 plants/m2.\nIn 2014, harvesting methods under no-wilting treatment were compared for flail-type harvesting\nwith a round-baler (Flail/baler plot) and mower conditioning with a round-baler (Mower/baler plot),\nwhich is common for beef-calfââ?¬â??producing farmers in the region. In 2015, the effect of ensilage with\nwilting was investigated only in the Mower/baler plot. Dwarf Napiergrass was cut twice, in early\nAugust (summer) and late November (late autumn), each year. The winter survival rate was greater\nthan 96% in May both years. The DM yield in the Mower/baler plot did not differ significantly for the\nfirst summer cutting or the annual total from the Flail/baler plot, but did show inferior yield for the\nsecond cutting. The fermentation quality of the second-cut plants, estimated using the V2-score, was\nhigher in the Flail/baler plot than in the Mower/baler plot, possibly because of higher air-tightness,\nand the second-cut silage tended to have better fermentation quality than the first-cut silage in both\nharvesting plots. Wilting improved the fermentation quality of dwarf Napiergrass silage in summer,\nbut not in autumn. The palatability of the silage, as estimated by alternative and voluntary intake\ntrials using Japanese Black beef cattle, did not differ significantly between plots. The results suggest\nthat dwarf Napiergrass can be better harvested using a mower conditioner with processing by a\nround-baler, an approach common to beef-calfââ?¬â??producing farmers, than with the flail/baler system,\nwithout reducing the persistence, yield, or palatability of the silage. Moreover, wilting treatment\nimproved the fermentation quality of the dwarf Napiergrass silage when processed in summer....
There is a need to develop alternative crops to improve the food security and prosperity\nof developing countries. The tropical nut Canarium indicum (canarium nut) is increasingly used\nas a shade tree for cocoa and has potential for commercialization as a sustainable crop that will\nimprove food security and livelihoods in Melanesia and East Asia. There is no information on\ncanarium nut shelf life characteristics. Canarium kernels may be prone to rancidity, due to a high\ncontent of unsaturated fatty acids. Kernels at 5.4% moisture content were vacuum-packed with a\ndomestic vacuum-packaging system and stored for six months in Papua New Guinea and for nine\nmonths in Southeast Queensland, Australia at both ambient temperatures (22 to 31 ââ??¦C and 22 to\n25 ââ??¦C, respectively) and under refrigeration. Nuts were analysed for changes in peroxide values\nand free fatty acids (FFAs) over the storage periods that might indicate development of rancidity.\nPeroxide values indicated very low levels of oxidation in all treatments. Free fatty acids were at low\nlevels but increased significantly during storage at ambient temperatures. The results suggested that\nvacuum-packed Canarium nuts can be stored safely under ambient tropical conditions for six months\nwith daytime temperatures around 31 ââ??¦C, and for nine months at 25 ââ??¦C. Increasing FFA levels at\nambient temperatures indicate caution about longer storage time at ambient temperatures. Storage\nunder refrigeration greatly prolonged shelf life....
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