ECONOMIC AND ENERGY VIABILITY OF SUNFLOWER IRRIGATED CROP

This study was carried out with the objective of assessing grain yield, economic analysis and energy balance of three sunflower genotypes with and without irrigation. The experiment was installed in the Experimental Farm of the Faculty of Agrarian Sciences of the Federal University of Grande Dourados in the 2011/2012 and 2012/2013 harvests in Dourados-MS, Brazil. The experimental design used was a random complete block design with subdivisions, with and without irrigation (plots), with three genotypes (subplots) and four replications, constituting 24 plots. There were no differences in productivity among the genotypes. The irrigation increased the operational cost of the sunflower crop production, but it did not economically obstruct the activity, due to the increase of productivity of 74.5% and 30% in the harvests of 2011/2012 and 2012/2013. The energy ratios of the sunflower crop were not altered by irrigation, equal to 5.7 and 8.7 in the harvests of 2011/2012 and 2012/2013, respectively.


INTRODUCTION
Among the several technologies developed for the sunflower production, the appropriate choice of genotype with h igh grain y ield co mprises the main co mponent of the crop production system (Porto et al., 2007).Despite the tolerance to water deficit when compared to other annual crops, sunflower is sensitive to the availability of water in the soil, increasing grain yield under irrigation (Go mes et al., 2012).
Since the adoption of the National Program for the Production and Use of Biodiesel, introduced in 2005, it has been growing the oilseed production in the country, especially in family agricu lture (there are incentives to the overwhelming power plants that buy from this sector); however, different fro m the expectation of diversificat ion, soybean cultivation continues to predominate (Silva, 2013).W ith technical assistance and structured production chain, sunflower cultivation could become an interesting alternative in the summer harvest, with higher oil productivity (Jasper et al., 2010) and lower production costs in relation to soybean (AGRIANUAL, 2012).
In addition to economic v iability, studies of the energy ratio in different production systems can provide subsidies for the Brazilian agriculture to become increasingly sustainable (Capellesso & Cazella, 2013).The energetic ratio can be obtained by the energy value of the productivity on all the energy expenditures coming fro m the imp lantation of the culture, being an important instrument of technological choice (Assenheimer et al., 2009), avoid ing and replacing the genotypes and productive systems with relat ion less than one (Albuquerque et al., 2007).
Irrigation is among the technologies that most contributes to the increase of productivity (Lira et al., 2015;Pereira et al., 2015); however, it also increases the input (consumption) of energy in the agricultural system.In this sense, some studies have been carried out over the last years aiming to analyze the energetic ratio of irrigated crops (Go mes et al., 2013, Jordan et al., 2012a;Jordan et al., 2012b).
This experiment was developed with the objective of performing economic analysis and energetic ratio of sunflower genotypes for two years, with and without irrigation, in the region of Dourados, Mato Grosso do Sul, Brazil.

MATERIAL AND MET HODS
The experiment was carried out at the Experimental Farm of the Faculty of Agricultural Sciences -FCA, Federal University of Grande Dourados -UFGD, in Dourados, Mato Grosso do Sul, located at the geographical coordinates 22 o 12' south latitude, 54 o 56' west longitude and average altitude of 452 m.
The climate of the region is classified by Köppen as Cwa (hu mid mesothermic with rainy summer).The soil of the experimental area is classified as Red Latosol Distroferric (EMBRAPA, 2006).The values of the chemical analysis of the soil referring to the depth of 0 -0.20 m are found in Tab le 1.For two years, the experimental area was prepared with plo wing and harrowing, 30 days before sowing, incorporating 1500 kg ha -1 and 1000 kg ha -1 of dolomitic limestone PRNT 80%, respectively, aiming to raise the base saturation by 70% (V).Afterwards, the irrigation system and the tensiometers were installed.In the sowings carried out on October 22 nd , 2011 and October 31 st , 2012, 150 kg ha -1 of the 8-20-20 formu lation and 1 kg ha -1 of boron in the form of borax were also applied.In the cover fertilization, 40 days after sowing (DAS), 50 kg ha -1 of nitrogen in the form o f urea was also applied.
The same experimental design was utilized in both years: random b locks, in schemes of subdivided plots, with and without irrigation (plots), with three genotypes (subplots) and four repetitions, comp rising 24 plots.The plots were implanted with an area of 36 m 2 , (15 m x 2.4 m), with four plant rows spaced in 0.60 m and with spacing between plants of 0.2 m.The subplots were implanted with 12 m 2 (5 m x 2.4 m).It was utilized genotypes from EM BRA PA: BRS 321, EM BRAPA 122 V2000 and BRS 323.
The irrigation system was assembled using three lines of dripping tapes between the plant rows, with spacing between the emitters of 0.40 m and drain of 3.65 L h -1 m -1 , to 100 kPa of service pressure, obtaining an application intensity of 6.1 mm h -1 .The service pressure was maintained by means of a drawer reg ister installed next to a pressure gauge with a resolution of 5 kPa.
Irrigation management was done from tensiometers installed at 0.2 m depth.The irrigation depth (ID) was determined by the difference between volumetric moisture in the field capacity (θ cc ) and the current volu metric humid ity (θ a ), mu ltiplied by the effective depth of the root, equal to 400 mm.The volu metric humidity was estimated by means of the soil water retention curve (θa = 0.4394 γ - 0.077 ; R 2 = 0.981).It was considered as soil water stress in the field capacity (γ cc ) the value of 6 kpa.Irrigation was suspended at 90 DAS (R8 stage -back of the yello wish chapter and green bracts).
Table 2 shows the values of temperature, relative humid ity, rainfall and irrigation in the experimental periods.Irrigated treatments received 270.9 mm and 290.5 mm of water depth in the first and second year, respectively.TABLE 2. Temperature (T), relative hu midity (RH), precip itation (P) and irrigation (I) during experimental cycles of sunflower cultivation *.
At the end of the cycles, on February 10 th , 2012 and February 18 th , 2013, 06 p lants were removed per subplot with the objective of evaluating productivity, correcting seed moisture to 13%.The productivity data were submitted to analysis of variance and Tukey tes t at 5% of probability.
The economic analysis was made based on the total production operating cost (TPO) and the effective operating cost (EOC), using market quotations.In the composition of the EOC it was considered the expenses with inputs, labor, electric energy in the case of irrigation, tax and revenue expenses.TPO was obtained by adding EOC plus capital depreciation (Mart in et al., 1994).
where, EOC -effective operating cost, R$ ha TOR -tax on revenue, R$ ha -1 ; EOR -expenditure on revenue, R$ ha -1 ; where, TPOtotal production operational cost, R$ ha -1 ; EOC -effective operational cost, R$ ha -1 , CD -capital depreciation, R$ ha -1 Because it is a self-propelled system (central pivot simu lation), it was not considered a labor increase due to irrigation.In the region there is still no charge fo r the use of water.
Fro m the applied irrigation depth, the simu lation was based on the power, mechanical efficiency and power factor of the electric motor of a central pivot water pump for 100 ha with flat topography, with electrical power required for pu mping the order of 1.472 kW ha -1 , which is considered in the calcu lation of the energy cost.It was also considered an application intensity of 0.43 mm h -1 and maintenance cost (MC) for central pivot estimated at 1.5% per year (Frizzone et al., 2005).The electric power was taxed according to the green horticultural price, adopting the energy prices (EP) established by CERGRA ND (Cooperative of Energizing and Rural Development of Grande Dourados) equal to R$ 0.2103 kWh -1 in the offpeak period with a discount of 80% fro m 9:30p m to 6:00am (R$ 0.0421 kWh -1 ).The monthly contracted demand rate (CDR), equal to R$ 13.96 kW -1 , was converted to R$ 20.55 ha -1 month -1 .It was considered a variable watering time for water depth equal to 9 mm, with irrigation time of 21 hours, avoiding peak time (5:30p m to 8:30p m) and obtaining, by weighted average, EP equal to R$ 0.1424 kWh -1 .The energy cost was estimated as follows: where, EP -energy price, R$ kW h -1 ; IT -Irrigation time per production cycle, h, CDR -contracted demand rate (R$ ha -1 ) The effective operating profit (EOP), which represents the economic viab ility in the short term, was obtained by the difference between the revenue (REV) and the effective operating cost (EOC): where, EOP -effective operational p rofit, R$ ha -1 , REV -revenue, R$ ha -1 Total operating profit (TOP), wh ich represents long-term economic viab ility, was obtained by the difference between gross revenue (GR) and total production operating cost (TPO): where, TOP -Total operational profit R$ ha -1 Capital depreciat ion (CD) was calculated using the capital recovery factor method (Tokairin et al., 2014), disregarding the residual value.In the case of irrigated plots, the irrigation system of the Central-Pivot type was considered (being the most used in irrigation of crops in the region), admitting a value of R$ 5500.00 ha -1 , according to average practiced price in 2011, using an interest rate (R) of 7.5% per year.For the Central-Pivot, it was used a 20-year life span (n) and use capacity equal to 2000 h year -1 (Frizzone et al., 2005).For the other mach ines and equipment, life values were adopted according to Pacheco (2000).
where, CD -capital depreciation, R$ ha -1 ; C -capital cost acquisition, R$ ha -1 ; R-annual interest rate, decimal; n -life span, years, F -rat io between hours of use per cycle and hours per year, decimal The energy viability analysis was performed using energy relations using the process analysis methodology (Hülsbergen et al., 2001): where, ERenergetic relationship, dimensionless; EE -ext racted energy, MJ ha -1 , UE -utilized energy, MJ ha -1 The UE was estimated as follows: where, ED -Energy depreciation of equip ment, MJ ha -1 ; EI -Energy demand for the use of inputs, MJ ha -1 ; EMO -energy employed in manual labor, MJ ha -1 , EEL -energy consumed in the form o f electricity, MJ ha -1 The energy required for the use of inputs was adopted according to values recommended by Hülsbergen et al. (2001) and Melo et al. (2007).Energy depreciation (ED) was estimated as reco mmended by Assenheimer et al. (2009), in the case of non-propelled equip ment (imp lements): In the case of the propelled equip ment (tractor and center pivot) the ED was calcu lated as follo ws: M -mass of machinery and equipment, kg, n -life span, h

Husage time per cycle, h
The mass of machines and equipment was adopted as recommended by Assenheimer et al. (2009) and the life span according to Chechetto et al. (2010).The mass of the central pivot irrigation system, equal to 57.2 kg m -1 , was obtained according to information fro m Valmont Industry and Co mmerce Ltd.

RES ULTS AND DISCUSS IONS
Productivity was affected by irrigation and harvests (P <0.05) independent of the cultivated genotype (P> 0.05).The highest yields were obtained in the 2012/2013 crop (Table 3), probably due to more favorable edaphoclimat ic conditions (Tables 1 and 2), such as elevation of base saturation (V), higher temperature and better distribution of rainfall, mainly fro m 41 to 60 DAS (stage R4 -opening of the inflorescence).
The yields of sunflower obtained under irrigation are above the values found by Guedes Filho et al. ( 2015) and Biscaro et al. (2008), both in second crop cultivation (small harest).In the 2012/2013 harvest, productivity under irrigation approached the mark of 4.000 kg ha -1 , surpassed in other surveys conducted in the first harvest (Anastasi et al., 2010, Go mes et al., 2012).* There weren't significant differences in yield between genotypes.** M eaningful differences between systems (small letters) and between crops (capital letters).
Considering the irrigation depths applied in the two years of experiment equal to 270.9 mm in 2011/ 2012 and 290.5 mm in 2012/ 2013 (Tab le 2), adopting application intensity of 0.43 mm h -1 , it was obtained in their respective years the irrigation time (IT) equal to 630 and 676 hours.Applying the equation 03, considering the energy price (EP) of R$ 0.1424 kWh -1 and the contracted demand cost (CDC) equal to R$ 20.55 ha -1 month -1 , during the harvests 2011/2012 and 2012/2013 the energy costs (EC) for irrigation was equal to R$ 234.81 ha -1 and R$ 244.45 ha -1 , respectively.
Table 4 shows the prices of the inputs used in sunflower cult ivation in the two years of experiment, equal to R$ 619.19 in 2011 and R$ 599.30 in 2012.Tab le 5 shows the capital depreciation of the machinery and implements, equal to R$ 62.10 per year.The used time of the plow and grid was measured at the site.In the treatments that received irrigation, it was also considered the depreciation of the Central-Pivot type system, equals to R$ 169.83 in 2011/2012 and R$ 181.16 in 2012/2013.The table 6 shows the average values of productivity (PROD), revenue (REV), tax (TAX) and expenditure on revenue (EOR) for sunflower genotypes, with and without irrigation.The REV was obtained from the prices practiced in the months of February 2012 and 2013, when the sunflower sacks were sold at R$ 47.32 and R$ 55.47, respectively.For the co mposition of the effective operational cost -EOC (Table 07), the labor expense was considered from the work of two emp loyees in the agricultural operations (4.63 hours each, equal to the time used of the tractor plus harvester -Table 05), considering the work hour of each equal to R$ 9.38 (R$ 1500.00 month -1 ), obtaining R$ 86.81 ha -1 .The revenue tax (TAX) and revenue on expenses (EOR) were obtained by applying percentages of 2.3% and 5% of revenues (REC), respectively (equation 01).The irrigation increased the effective operating cost (EOC) of production by 41% and 36% in the 2011/2012 and 2012/2013 harvests, respectively.The increase in total production operational cost (TPO) with irrigation was 56% and 52% in the 2011/2012 and 2012/2013 harvest seasons, respectively.These costs were offset by increased productivity under irrigation, with increases of 127% and 27% for effective operational p rofit (EOP) in the harvests of 2011/ 2012 and 2012/ 2013, respectively (equation 04).The total operating profit (TOP) under irrigation obtained an increase of 108% and 18% in the harvests of 2011/2012 and 2012/ 2013, respectively (equation 05).
These results make feasible the irrigation technique in short (EOP) and long term (TOP).Guedes Filho et al. (2015), conducting the sunflower experiment under irrigation with the genotype EMBRAPA 122/ V-2000, reached an average productivity of 2494 kg ha -1 with 100 kg ha -1 de N, and observed viability only in the short term.At the time the value of the bag was R$ 31.80.
At the current conjuncture, it seems unlikely the long term economic inviab ility for irrigated sunflower cultivation, since only the activity would become impracticab le at a price lower than R$ 27.50 a bag, or else (if the price of the bag remains at R$ 50.00) with the productivity less than 30 bags ha -1 (1800 kg ha -1 ).
The energy used in sunflower cultivation through inputs was 8564.76 and 7964.76MJ ha -1 (average value as 8265 MJ ha -1 ), in the harvests of 2011/2012 and 2012/2013, respectively (Table 8), that is, 98.8% of the average energy used (EU) without irrigation (Table 11).Jordan et al. (2012a) also found that inputs were responsible for mo re than 90% of the energy demand in sunflower cultivation without irrigation.In general, inputs are main ly responsible for energy demand in conventional agriculture (Checheto et al., 2010;Go mes et al., 2013).The average energy used (EU) to produce the sunflower crop without irrigation was 8365 MJ ha -1 (Table 10), with 100.03MJ consumed in the form of energy depreciation (Table 9), 9 MJ of energy of hand of (EHO).In the estimation of EHO it was considered a daily requirement (8 hours) of 2000 kcal (8.38 MJ), with 4.3 hours of work (the same as mach ine hours), emp loying two employees in agricultural operations.Table 10 shows the energy consumed by irrigation in the form of electric energy (EEL) and energy depreciation (ED), adding an average energy demand of 3827 MJ ha -1 , that is, an increase in consumption Energy consumption of 45.8% due to irrigation, main ly because of electricity.The highest energy ratio was obtained in the 2012/2013 harvest (p <0.05); however, without effect under irrigation (p> 0.05) (Table 11).Contrary behavior was verified by Jordan et al. (2012a), in a study conducted with the sunflower crop, where the energy ratio was lower with irrigation.

CONCLUS IONS
1.The sunflower genotypes showed similar yields in both years; 2. The cultivation of the irrigated sunflower crop is economically v iable in a short and long term; 3. The irrigation does not alter the energy ratio of the sunflower crop; 4. The highest economic return and higher energy ratio occurs in the 2012/2013 crop due to higher yield.

TABLE 1 .
Chemical analysis of the soil in the 0 -0.20 m layer of the experiment with irrigated and non-irrigated sunflower in the years 2011/2012 and 2012/2013.

TABLE 4 .
Prices of Input used in the sunflower crops*.

TABLE 5 .
Capital depreciation and maintenance cost of machines, imp lements and irrigation system.

TABLE 6 .
Productivity, inco me, tax and expenses of sunflower cultivation with and without irrigation in the harvests of 2011/2012 and 2012/2013.

TABLE 7 .
Costs and operating profits fro m sunflower cult ivation in the harvests of 2011/2012 and 2012/2013.

TABLE 8 .
Energy demanded for the use of inputs (EI) used in sunflower cultivation.

TABLE 9 .
Energy depreciation (ED) as a function of the time using machines and equipment used in the cultivation of sunflower in a conventional system.

TABLE 10 .
Energy spend in the form of electricity (EEL) and energy depreciation (ED) in the irrigation system

TABLE 11 .
Used energy (UE), ext racted energy (EE), energy ratio (ER) with and without irrigation in the sunflower crop.