Fuel consumption of a machine-tractor unit in direct sowing of wheat

G. Tihanov1*, N. Ivanov2

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Plant production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 7 September 2020; accepted for publication 8 January 2020)

Abstract. A study has been conducted on the fuel consumption in direct sowing of wheat with a Horsch Avatar 6.16 SD direct seeder aggregated to a John Deere 7250 R tractor. The experimental field (29.53 ha) was sown with winter soft wheat (Silverio variety) at a sowing rate of 195 kg/ha. The data from the sowing unit were collected using the JD Link telematics system, downloaded from the system and imported and compiled in a database. Fuel consumption was analyzed in accordance with the operation mode, the idle mode and the transportion mode of the machine-tractor unit. It was found that the average fuel consumption in work mode (when the seeder was sowing) was 23.08 l/h, while in transportion mode the seeding unit consumed 16.55 l/h and while the unit was idling it consumed 4.30 l/h. The results also show that the seeding unit has travelled 63 km and consumed 185 L of diesel fuel at an average diesel consumption of 23.08 l/h.

Evapotranspiration in Sudan grass second culture grown under non – irrigated and optimal irrigated conditions

R. Bazitov*

Agricultural institute, 6000 Stara Zagora, Bulgaria

(Manuscript received 24 August 2020; accepted for publication 19 October 2020)

Abstract: The aim of the present study was to establish the evapotranspiration of Sudan grass variety Engje-1, grown as a second crop for silage on meadow-cinnamon soil for the region of Southern Bulgaria under irrigation conditions and without irrigation. For this purpose, an experiment with Sudan variety Endje-1 was conducted in the experimental field of the Agricultural Institute – Stara Zagora on soil type meadow-cinnamon soil, after its predecessor barley. The Sudan grass is harvested in the brooming stage. Two variants were explored: Variant 1 – without irrigation (control) and Variant 2 – with optimal irrigation, 70-75% of field capacity (FC). Evapotranspiration of Sudan grass grown as a second crop under non-irrigated conditions, depending on the nature of the year, ranges from 168.7 mm to 183.7 mm. Under conditions of irrigation, the largest share in the formation of the water consumption is occupied by the irrigation norm – 87.1% on average (from 86.3 to 90.8%). Under irrigated conditions, the relative participation of the initial water reserve in the formation of evapotranspiration significantly decreases.

Operational characteristics of direct sowing machine-tractor unit

G. Tihanov*

Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 13 July 2020; accepted for publication 26 October 2020)

Abstract. A study on some operational characteristics of a direct sowing machine-tractor unit has been carried out in wheat sowing. It is performed by Horsch Avatar 6.16 SD direct seeder aggregated to John Deere 7250 R tractor. It was found that 91% of the area is sown at sowing rate of 195 kg seed/ha. The remaining 9% are sown either at lower or higher rate. Engine rotations of the seed unit have been established at work mode, i.e. when the seeder is sowing, these are 1594.81 min-1, in idle state the rotations are 912.08 min-1, and in transportation mode are 1860.36 min-1. The relative share of engine use has also been determined: when the seeder is sowing, it is 56.68%, when the seeder unit is in idle mode, it is 14.54% and when the unit is in transportation mode – 28.78%, respectively. The actual operation speed of the seeder unit when sowing wheat was 10.40 km/h and the real hourly productivity – 3.7 ha/h.

Growth and yield of orange (Washington Navel 141) grafted on different citrus rootstocks

Alaa Suhiel Ibrahim*

Research station of Ciano, Jableh, the agricultural scientific research center in Lattakia, General corps of scientific agricultural researches, Syria

(Manuscript received 26 May 2020; accepted for publication 27 July 2020)

Abstract. This investigation was conducted during 2014, 2015 and 2016 in the field of the citrus experimental station in Ciano, the general corps of scientific agricultural researches. The growth and yield of orange trees (Washington navel 141) budded on seven citrus rootstocks (Sour orange, Troyer citrange, Carrizo citrange, Citrumelo 4475, Citrumelo 1452, Macrophylla and Cleopatra mandarin) and farmed since 1989 have been studied. The results for the average of yield showed that the trees grafted on Cleopatra mandarin (58.33 kg. tree-1) were significantly superior to those grafted on Macrophylla (34.17 kg. tree-1). Orange trees grafted on Citrumelo 4475 and Citrumelo 1452 were significantly superior to other treatments in trunk section area of the rootstock (922.41 and 841.02 cm2, respectively). The greatest fruit fresh weight was in trees grafted on Citrumelo 4475 (284.85 g. fruit-1) which were significantly superior to those grafted on Carrizo and Troyer citrange (232.49 and 236.06 g. fruit-1, respectively). The biggest total soluble solids (%) was in trees grafted on Carrizo and Troyer citrange (12.83% for both treatments) which were significantly superior to those grafted on Sour orangе and Macrophylla (11.5% for both treatments), while the greatest total acids (%) was by Sour orange (2.08%) without significant differences.

Spectral analysis as an extra method to soil type discrimination

M. Todorova1*, S. Atanassova2, M. Georgiev1, L. Pleshkuza1

1Department of Crop production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria,
2Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University,
6000 Stara Zagora, Bulgaria

(Manuscript received 18 February 2020; accepted for publication 25 April 2020)

Abstract. The purpose of the study was to test near infrared soil spectra as an extra method for three soil types (Fluvisols, Vertisols and Solonchaks) discrimination from different regions of South Bulgaria. The diffuse reflectance spectra of 177 soil samples (from the 0-20cm layers): 50 samples of Fluvisols soil type, 78 samples of Vertisols soil type and 48 samples of Solonchaks soil type were obtained using a Spectrum NIRQuest (OceanOptics, Inc.) working within the range from 900 to 1700 nm. Soft independent modelling of class analogy (SIMCA) was performed to classify samples according to their taxonomic classes. The results obtained showed that the soil samples are separated accurately according to their soil type based on their spectral information. All this could be used in the future studies related to the application of the NIRS method as a qualitative or quantitative method for soil analysis and also for the purposes of precision farming.

Еconomic analysis of meat production from two types of Domestic quails

H. Lukanov1*, I. Pavlova2

1Department of Animal Science – monogastric and other animals, Faculty of Agriculture, Trakia University,

6000 Stara Zagora, Bulgaria

2Department of General livestock breeding, Faculty of Veterinary medicine, Trakia University,

6000 Stara Zagora, Bulgaria

(Manuscript received 3 March 2019; accepted for publication 17 April 2020)

Abstract. There are two types of Japanese quails, reared in Europe – dual-purpose and meat. The aim of the present study was to made an economic analysis of fattening quails from the dual-purpose and heavy production types. Three groups were formed – group 1 (dual-purpose), groups 2 and 3 (heavy type), reared in cages. After quails sexing on the 16th day of age, there were formed six subgroups: 1m, 1f, 2m, 2f, 3m and 3f. Fattening period lasted until 35 days of age. For revenues calculation produced meat and edible offal data per m2, were used. Costs calculation include consumed feed for the period, day-old quail, and other costs. The main production costs were associated with feed and day-old quails: from 80.3 and 82.6% of all costs in the studied groups. The anticipated revenues from produce in group 2 were 10 EUR/m2 higher than those in group 1, and for group 3 – 10.21 EUR/m2 higher than group А. The results indicate that meat type quails fattening is the most economically efficient in quail meat production. Producing quail edible offal is still not developed but could be beneficial for efficiency of quail fattening small farms.

Evaluation of new mathematical models for estimation of single olive leaves area

M.A. Mhanna*

General Commission for scientific agricultural research, Latakia research center, Ciano research station,

Latakia, Syria

(Manuscript received 7 March 2020; accepted for publication 24 April 2020)

Abstract. The study was conducted on “Khoderi” olive cultivar planted in Jableh Region-Latakia province, Syria in 2017 in order to evaluate some mathematical models adapted for olive single leaf area estimation. Leaf samples were taken from the middle of one-year branches. Actual areas of the leaves were measured using Adobe Photoshop CS5. Leaf dimensions (length and width) were measured accurately. Coefficients of determination were estimated for the relation between leaf dimensions and the actual area. The best coefficient of determination was between the natural logarithm of the product (leaf length × leaf width) and the natural logarithm of leaf area (R2= 0.962). Linear regression equation of the mentioned relation was fitted and evaluated. The accuracy of the new model (A=e0.9509ln LW – 0.2867) was compared to other models commonly used for olive single leaf area estimation. The comparison showed no significant differences between leaf area obtained by the new model and the actual leaf area values (p=0.01), whereas significant differences were found for the other models. The new model showed the lowest Root Mean Square Error (RMSE) and high efficiency in estimating olive leaf area of “Khoderi” cultivar in two different environments; the same results were obtained for olive cultivar “Picholine” the French. We recommend the new model for olive single leaf area estimation.

A study on the hopper unloading duration of the harvesting machine at different technical parameters

G. Tihanov*

Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 10 December 2019; accepted for publication 20 February 2020)

Abstract. When unloading grain harvester hoppers at standstill the time of emptying the hopper has a significant effect on the harvester productivity. The paper is about a conducted survey in 15 agricultural farms with 15 harvesters monitored including 14 models of 6 different brands during wheat harvesting. The time for emptying the grain hopper of the harvesters was defined by measuring the time. It was found that the actual time for emptying the hoppers of the studied harvesters was 134.85 s, and the actual flow rate of unloading of the screw in them being 69.63 L/s on average. A multivariate regression analysis was performed on the effect of the harvester grain hopper volume and the actual flow rate of the unloading screw on the time from switching on the unloading screw till its switching off in various grain harvesters. An adequate mathematical model of the effect of the hopper volume and the flow rate of the unloading screw of grain harvesters on the time for emptying the grain hopper under real production conditions has also been created. These results can also be used for minimizing costs in the technological process at harvesting.

Stochastic production function and costs-returns analyses of apiarists in Adamawa State, Nigeria

M.M. Audu, M.R. Ja’afar-Furo*, B.H. Gabdo

Department of Agricultural Economics and Extension, Faculty of Agriculture, Adamawa State University, PMB 25, Mubi, Nigeria

(Manuscript received 23 September 2019; accepted for publication 14 February 2020)

Abstract. This study assessed apiculture enterprise to determine the output elasticity of production, returns to scale, technical efficiency and profitability in Adamawa State, Nigeria. A total of four agricultural zones out of six, and 108 apiarists were selected through purposive and simple random methods, respectively. Descriptive statistics, stochastic frontier production function and budgetary technique were used in the analyses of data. Findings revealed that all (100%) the respondents were males within the age range of 21-30 years (44.44%). The majority of apiarists (87.0%) were married with household size of 1-10 persons (77.78%) and 50.0% of them had secondary school education. A larger proportion (37.0%) had between 6 and 10 years of beekeeping experience with 41.67% earning monthly income of N11000 (USD30.8) – N20000 (USD56.0) from other sources. Further, the findings revealed that labor and number of hives had reassuring influence on the industry, while age, education and experience could be used to reduce inefficiency in the industry to improve efficiency status. The apiarists also had mean technical efficiency of 89.9%, while the inefficiency estimate was only 10.1%. In terms of profitability, beekeeping in the study area was found to have had a high gross margin of N16800.00 (USD47.0) and net farm income of N15225.97 (USD42.6) for every beehive in a cropping season. The major constraints to beekeeping reported in the area included beehive crops theft, high propensity of bees’ stings, inadequacy of finance, rampant bush burning and deforestation, among others. It was concluded that beekeeping in the study area was found to be profitable and technically efficient. Improving beekeeping business in the area, among other things, would require its modernization and involvement of female participants, provision of soft credit facilities and enactment of stringent forestry laws to check unwholesome forestry practices.

Economic efficiency of Bulgarian dairy synthetic population and Assaf sheep breeds

K. Stankov*
Department of Management, Faculty of Economics, Trakia University, 6000 Stara Zagora, Bulgaria (Manuscript received 1 December 2019; accepted for publication 28 February 2020)

Abstract. The economic efficiency of ewes from the Bulgarian dairy synthetic population (BDSP) and Assaf sheep breeds, reared in three production systems, e.g. grazing on pasture, stall-pasture rearing and stall rearing was studied. The results from the study showed that BDSP ewes in the stall-pasture rearing system had a relatively low milk yield for a specialised dairy sheep breed – 80L for the lactation period. In this system, without the subsidy, the profit and cost efficiency were negative, while with subsidy, minimum positive results were achieved. For BDSP ewes reared in a stall-pasture rearing system with stall feeding during the grazing period and grazing on improved pastures, the obtained milk yield was by 33% higher. The subsidy resulted in satisfactory profit and cost efficiency, while without the subsidy, the farm ended in loss. BDSP and Assaf ewes reared in stalls, demonstrated substantially higher milk yield and productivity. They realised a profit and good cost efficiency. The milk yield of BSDP sheep reared in stalls was 200L per lactation, and fertility – 140%. The Assaf breed in which a high level of selection and regulated reproduction cycle was achieved, had 250L milk per lactation and 140% fertility. The profit with subsidy was 128.85 BGN (1Lev=0.975€) and without the subsidy: 48.85 BGN, with relatively high cost efficiency. An introduction of traits for higher milk yield, polyestrus and fertility from Assaf into BSDP sheep is necessary.