Optimum Replacement Time for Cotton Pickers in Greece

In this paper an attempt has been made to determine the optimum replacement time for cotton pickers under the technical and economic conditions in Greece. For this purpose, five relevant methods have been applied to analyze real data taken by 62 cotton pickers working in Central Greece. Three of the methods consider that the optimum replacement time for cotton pickers is the year when the accumulated annual depreciation is equal to the corresponding repair and maintenance costs or the year when the aforementioned annual expenses of the machine per working hour are minimum. The fourth method considers the year in which the accumulated average total costs per working hour or per hectare harvested is minimum, while the fifth method refers to the year in which the accumulated annual “standardized†net income received from the use of a cotton picker is maximum. Based on the results of this study the optimum replacement time of a cotton picker is the 14th –15th year of its productive life combined with 4500 –5000 working hours and 1450 – 1550 hectares harvested.cotton pickers, optimum replacement time, costs, net income, Farm Management, Crop Production/Industries,

Energy balance of sunflower production

ArticleThe aim of the present study was to make an energy analysis of sunflower crop in the Trakya Region of Turkey, to evaluate the potential for using it as bioenergy source. Actual data for the common cropping practices applied in the region were collected with questionnaires given to the farmers. Literature data were used to obtain necessary energy indices. The collected information was used to establish energy budgets. Two alternative scenarios were examined: 1st - Using only the seed for biofuel production and 2nd -using the seed for biofuel and the stalks as biomass for bioenergy. The results showed that sunflower presented positive energy balance for both cases. Net energy was 35,334 MJ ha-1 when only the seed was taken into account and 87,308 MJ ha-1 for both seed and stalks. Energy efficiency was 3.67 and 7.34 respectively. Fertilization was the most energy intensive input (6,594 MJ ha-1 ) accounting for 48–50% of the total inputs. Tillage was the second most energy intensive input (3,595 MJ ha-1 ) accounting for 26–27% of total inputs. There were 6 different tillage operations such as ploughing, 4 machinery passages for seedbed preparation and hoeing in the sunflower production. All these operations increased energy inputs of the tillage. The total energy inputs were relatively low because it was possible to achieve high yields without irrigation

Interrill Soil Erosion as Affected by Tillage Methods under Cotton in Greece

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 8 (2006): Interrill Soil Erosion as Affected by Tillage Methods under Cotton in Greece. Manuscript LW 05 006. Vol. VIII. February, 2006

Fossil Fuel Deficit-Conservation Tillage and on Farm Biofuel Production to Cope With the Problem

Abstract The limited resources of fossil fuels along with the highly fluctuating prices, call for investigation to find diesel alternatives. Biofuels from vegetable oils, seems the easiest accessible substitutes as they can be used in conventional diesel engines without lot of modifications. There are though two mainstream attitudes on this approach. The one points that it is immoral to divert environmental resources from food production to energy production when the global population increases and the other claims that without mechanization and fuel to power it, food production will finally be decreased. Conservation tillage adoption may contribute in significant fuel savings by eliminating tillage operations. If they would be combined with on farm biofuel production, they would certainly require less land to be devoted for this purpose. In the present work, based on data of a long term tillage experiment, it was calculated the percentage of land that would be required to cultivate with a biofuel crop (sunflower for instance) in order to cover the fuel requirements of an arable farm, for three alternative tillage methods: conventional (CT), reduced (RT) and no-tillage (NT). The results indicated that in CT, the 11% of the land would be enough to provide the biofuel for all the field operations (except irrigation). In RT, due to lower fuel consumption, the 7.5% of the land would be sufficient. That means that a 3.6% yield reduction is justified. In NT, only the 3.5% of the land is required to produce the biofuels justifying a 7.7% yield reduction. This sets the limits of yield reduction that can be acceptable. However we have to add in this balance the environmental effects of using conservation tillage like erosion reduction, increasing soil organic matter and biodiversity maintenance

Energy budget of a method to harvest cotton stalks

The energy budget of a method to harvest cotton stalks developed and tested in Greece is reported in the present paper. The method used conventional hay harvesting machinery. An instrumented tractor was used to measure the energy consumption during the work in the field while literature data were used for the indirect energy sequested to the machinery used. The results showed that a net energy of 35,498 MJ/ha can be produced from cotton field every year, indicating the interest for this residue use. (C) 1998 Elsevier Science Ltd. All rights reserved

Harvesting of cotton residue for energy production

The possibility of collecting cotton stalks in Greece and using them for energy production was investigated. The production and properties of cotton stalks were studied and a system for collection of the aerial part is proposed as a feasible solution to avoid wet conditions under the local climate. A successful method for collection and packaging of the residue was applied, using conventional but highly advantageous equipment, offering reduced investment cost and use of existing machinery. The energy required to harvest cotton stalks was measured by an instrumented tractor. The tractor was able to measure the developed forces between tractor and implement, the power absorbed through the PTO, as well as tractor velocity and fuel consumption. The energy consumed for the operation was calculated and when compared to the energy of the biomass collected gave a positive balance. The work proved the feasibility of harvesting cotton stalks using conventional machinery giving the possibility to collect energy material with a total energy content of 500,000 tons of oil equivalent at national level. (C) 1999 Elsevier Science Ltd. All rights reserved

Effects of soil compaction, water and organic matter contents on emergence and initial plant growth of cotton and sugar beet

The effects of compaction on the emergence and initial growth of cotton and sugar beet plants were studied in pots in a glasshouse experiment. Apart from compaction, the factors studied were two soil types, two initial soil water contents before compaction and the addition of 1% organic matter in the form of vinasse, an alcohol industry waste. Measurements were made of the time to emergence, the daily growth and the final height of the plants after 30 d and the dry matter of the aerial and root parts. A completely randomised block experiment was made with four replications. The results showed that sugar beet is more sensitive to compaction than cotton. Compaction reduced the amount of root dry matter but the aerial part was less affected. Time to emergence was reduced at moderate compaction (around 150 to 200 kPa) and high initial soil water content (15% for the sandy loam and 23% for the clay loam). Mean daily growth and final height of plants showed a maximum at compaction pressures around 100 to 200 kPa. Increased organic matter caused a smaller increase in the bulk density of the soil by compaction but the effect on plants was not clearly revealed because of the adverse effect of the material on emergence time, most probably owing to the sodium content and to the low pH. (C) 1997 Silsoe Research Institute

Sugar beet genotype response to soil compaction stress

Eleven sugar beet genotypes were tested for their performance under different soil compaction levels. The genotypes used were three inbreds, three commercial varieties widely cropped in Greece, four experimental hybrid varieties and two multigerm OP lines. The experiment was conducted in pots in glasshouse. Pots were filled with soil and after placing the seed at a depth of 3 cm, the compaction pressure was applied. Two soil types, two initial soil water contents and seven pressure levels ranging from a minimum pressure up to 400 kPa were the factors studied in a randomised complete block experiment with four replications. Results showed that sugar beet is sensitive to compaction although low compaction pressures (less than 200 kPa) seemed to be beneficial. From the genotypes tested inbreds were more sensitive to pressure effects than hybrids. Differences among hybrid varieties were observed indicating that response to soil compaction effect could be genotypically affected. This was further confirmed by the different response between the multigerm open polinated varieties (C) 2000 Elsevier Science B.V. All rights reserved

Transplanting Machine Operation Analysis

Transplanting has been used for most vegetables and ornamental plants to achieve better establishment and early maturing of the crops. Manual transplanting is slow and labour intensive. Semiautomatic transplanters are a low capital alternative that can increase productivity, speed of work and lower costs. In the present paper a comparison between the manual and semi-automatic transplanting was carried out during field work. Leaks, cabbage and peppers were transplanted in parallel rows manually and mechanically. The results showed that the cost for automatic transplanting was 73-86 % lower than manual transplanting, while the operating performance was 32.7-38.5 % higher with the semiautomatic transplanter. It was also shown that the performance of the workers on the transplanter increased with experience gained while working continually for six working days