Organic and Mineral Fertilizer on the Initial Development and Nutrition of Jatropha

Jatropha (Jatropha curcas L.) is an herbaceous plant, perennial, belonging to the family of Euphorbiaceaes. Jatropha’s extract is used for the harvest of fruits, high amount of nutrients and, if not properly fertilized, can lead to the impoverishment of the soil over the years of cultivation. Thus, in this present work, we have a concern with the importance of fertilization. The experiment was conducted under field conditions in the 2014/2015 agricultural year, in São Jorge do Patrocínio, State of Parana, Brazil. The experiment was conducted in a randomized block design with five replications and five treatments, totaling 25 installments. The treatments were as follows: organic fertilization (total rate: 2,800 g plant), mineral fertilizers with nitrogen, phosphorus and potassium (total rate: 174.4 g plant, and 13.2 g plant of urea, 141.2 g plant of superphosphate and 20 g plant of potassium chloride), 75% organic fertilizer + 25% mineral, 50% organic fertilizer + 50% mineral, 25% organic + 75% mineral, applied at planting. Poultry litter was used as the organic fertilizer source, the nitrogen source was urea, the phosphorus source was superphosphate and, the potassium source was potassium chloride. Spacing of 2 × 2 m between plants and the pits with 30 × 30 × 30 cm. The evaluated variables were: plant height, stem diameter, contents macro and micronutrients in leaves. It can be concluded that there was no influence of mineral and organic fertilization on the initial growth of jatropha. As for the macronutrient levels, there were no significant differences for P and K. However, regarding the mineral fertilizer and the micronutrient content, there was a significant difference in Mn, in the treatment with total rate of mineral fertilizer and in the treatment with 25% organic fertilizer and 75% mineral fertilizer.


Introduction
The Euphorbiaceae family comprises approximately 8000 species, with about 320 genera.The Jatropha genus contains approximately 160 species of herbaceous and shrub plants, of which medicinal, ornamental value and others produce oil, as is the case of Jatropha curcas L. (Nunes & Paqual 2007).
The jatropha plant may have various uses, such as: medicinal, ornamental, hedge and oil production.The pie remaining from seed pressing is a fertilizer rich in nitrogen, potassium, phosphorus and organic matter, but it is not recommended for use in animal feed without adequate treatment.Another use of jatropha solid wastes can be, as observed in other organic wastes, such as pine bark, its use as charcoal and raw material in papermaking and boiler feed for steam production and bioelectricity (Gusmão, 2010).routes, presenting physico-chemical characteristics compatible with Resolution 42 of the National Petroleum Agency (ANP) (Araújo et al., 2007).
The seeds are the oil source in the jatropha plant.Dantas et al. (2009), and Morais et al. (2007), state that the production and commercialization of high quality physiological jatropha seeds, one should harvest the yellowish fruits with brown parts.
According to Laviola and Dias (2008), jatropha extracts a high amount of nutrients from fruit harvesting and, if not properly fertilized, it can lead to soil impoverishment over the growing years.
Additionally, the response of the Jatropha culture to a monoculture system shows that it is a plant susceptible to pests, diseases, water deficit and soils with low fertility.The occurrence of diseases and pest attacks has been widely reported in experimental and commercial plantations in Brazil and in the world (Heller, 1996;Saturnino et al., 2005;Jongschaap et al., 2007;Gonçalves et al., 2009).
Studies on jatropha are mostly restricted to the young plant, with one or two years of cultivation.Since it is a perennial crop and reaches its peak of production around the 5th year of cultivation, there is a greater need for studies on year-to-year fertilization.
The aim of the present study was to evaluate the effect of organic and mineral fertilization on initial growth of jatropha, as well as its nutrition.

Method
The experiment was conducted under field conditions in the 2014/2015 agricultural year of, located in the city of São Jorge do Patrocínio, whose latitude and longitude are 23°45′45″ S, 53°52′39″ W, respectively.According to the climate classification of Köppen-Geiger, the climate is humid subtropical.
The experiment was carried out in a randomized complete block design, with five treatments and five replications, totaling 25 plots.The studies involving chemical and organic fertilization for the jatropha culture are still incipient, and sometimes provide divergent technical information, Although there are different studies, in which there is a lack of information on crop conditions (soil, climate and management), we used the recommended fertilization for castor bean in this experiment, according to Savi Filho (1998), which consists of mineral fertilization with 15 kg ha -1 of N, 60 kg ha -1 of P 2 O 5 and 30 kg ha -1 of K 2 O.
Regarding, as for organic fertilization, the chicken manure (with fattening residues from two lots of chickens with periods of 43 days each), the dose of 7 t ha -1 was used.The treatments were as it follows: organic fertilization (total dose: 2,800 g plant -1 ), mineral fertilization with nitrogen, phosphorus and potassium (total dose: 174.4 g plant -1 , being 13.2 g plant -1 urea, 141.2 g plant -1 simple superphosphate and 20 g plant -1 potassium chloride), 75% organic fertilization + 25% mineral, 50% organic fertilization + 50% mineral, 25% organic fertilization + 75% mineral fertilization, applied at the time of planting.Concerning, as for organic fertilization, we used, chicken manure as biofertilization source.As for mineral fertilization, the source of nitrogen was urea, for phosphorus, simple superphosphate and for potassium, potassium chloride.It was used 2 × 2 m of spacing between plants and in the pits 30 × 30 × 30 cm were used.
The planting area was desiccated and the planting was done manually on June 28, 2014, whose seeds for seedling formation were sown in substrate tubes on April 21, 2014.Weeds were eliminated soon after its emergence, and there was no need for control of pests and diseases.Every 30 days, during the 12-month period, the following characteristics were evaluated: plant height and plant stem diameter, with the aid of a measuring tape and a caliper rule, respectively.A leaf diagnosis was made using 10 leaves of each experimental plot, collected after 06 months and at the height of the middle third of the plant, being washed with distilled water and placed in a forced air ventilation oven at 60-70 ºC, for 72 hours.Macronutrients (P, K, Ca and Mg) and micronutrients (B, Zn, Fe and Mn) were analyzed following the methodology of Malavolta, Vitti, and Oliveira (1997), and all samples were ground in a stainless steel mill, weighed and placed in test tubes, which were placed in digestion blocks, using the digester solution and the perchloric nitric acid together with the samples.After digestion, the samples were submitted to the analyzes already mentioned.
Statistical analysis was performed following the variance analysis model, using the Sisvar program, using the 5% level of significance.The averages were compared by the Tukey test, with the same level of significance.

Results
For plant height, there was no significant difference between treatments (Table 1).Through the soil analysis it is possible to interpret that nutrient K was at medium level and this may have led to the not significant results of fertilization management, since the soil exhibited chemical characteristics relatively adequate to the plants still in early development, ally to the irregular rainfall, limiting growth characteristics (height and stem diameter).Note.n.s.= not significant; C.V. = coefficient of variation.
For plant stem diameter, no significant difference was found between fertilization management (Table 2).Note.n.s.= not significant; C.V. = coefficient of variation.
A significant difference was observed in the treatment with mineral fertilization in the phosphorus (P) and potassium (K) contents.The analysis of variance indicates that the treatment with mineral fertilization favored the levels of the macronutrients P and K, compared to the other treatments used.
In Table 4, it is possible to observe the significant difference in the treatment with mineral fertilization (total dose and 25% O + 75% M) only in the manganese content.

Discussion
In other studies, contrasting results about of Jatropha and other plant species were observed in treatments with fertilization.In the experiment on nutrient omission in jatropha plants grown in nutrient solution, Maia et al. (2014), observed that the absence of N and P were the ones that affected the macronutrient contents in the aerial part of the jatropha plants, promoting uniform chlorosis of the leaf blades.In the study on Jatropha response to the application of irrigation levels and doses of potassium fertilization, Oliveira et al. (2012), observed that only potassium fertilization, did not affect the growth of irrigated jatropha in the southern region of Minas Gerais.
In the castor bean crop, Severino et al. (2011), found a significant increase in productivity and growth characteristics of the castor bean with the supply of chemical or organic fertilization (average of all treatments that received any fertilization).In addition, the supply of micronutrients associated with adequate doses of organic and mineral fertilizer significantly increased the diameter of the stem.
When comparing organic and mineral fertilization, Carvalho et al. (2011) studied the use of mineral fertilizer and aviary bed, which were applied at the time of sowing, and observed that the height of the soybean plant responded significantly for both treatments.The authors state that this occurred because the experiment was conducted in soil with low fertility and no acidity correction, conditions contrary to those of the present study in which the soil, although sandy, exhibited close to 60% saturation.
Mineral fertilizers are inorganic salts of different solubilities.The agronomic efficiency depends on its solubility and the chemical reactions with the soil.Nitrogen fertilizers are completely soluble in the soil and can be partially leached.Potassium fertilizers are also soluble, but they present lower losses due to leaching, since the K+ ion is retained at the soil exchange sites, and only the portion at soil solution is removed by water.Phosphate fertilizers have a very variable solubility, depending on the type of phosphate, the thermal or chemical treatment given to the phosphate rock and the predominant soil type (sand, silt or clay) (Giracca & Nunes, 2012).
In order that the organic material added to the soil can supply nutrients to the plants, it must be decomposed by the soil microorganisms, and the nutrients retained in its organic structures be released (mineralized).This process of mineralization is influenced by characteristics of the organic material and the environmental conditions of temperature, humidity, aeration and acidity (Correia & Andrade, 1999).Figueroa et al. (2012) found that the use of chicken manure doses did not increase the levels of phosphorus, potassium, calcium, magnesium and micronutrients in wheat grains.Carvalho et al. (2011) compared the conventional mineral fertilization and the use of chicken litter in soybean, and verified that soybean yield with chicken manure application was similar to that obtained by the use of mineral fertilizer, only at very high doses of organic fertilizer.
For Kumar and Pandey (1979), elements with high mobility in the phloem, such as N, P and K, are found in greater quantities in the younger leaves.However, nutrients such as calcium (Ca) and magnesium (Mg) tend to concentrate in older tissues in function of the low redistribution capacity (Pathar & Pandey, 1976, Caldeira et al., 2002).Phosphorus has great mobility in the phloem and is a nutrient closely linked to the physiological processes of energy flow (Marschner, 2002).
The Mn is considered an element of low mobility in the phloem (Marschner, 2002).In older leaves Mn tends to accumulate and is not influenced by the presence of flowers on the branch (Pathar & Pandey, 1976).
Among other factors, variations in leaf nutrient accumulation may be related to the stage of development of the plant and leaves, the position of the leaf in the branch, the type of branch and the period of sampling (Freiberger, 2012).Lima et al. (2011a) concluded that the 2nd and the 3rd jatropha leaves nodes, from the apex direction to the based of the secondary branches, are the most suitable for leaf analysis of N, P, K, S, Cu, Fe, Mn and Zn, which present more stable average values when compared to other studied positions.These authors also determined that the 5th and the 10th leaves nodes are more appropriate for evaluation of Ca and Mg and that the phenological stage of the branch does not influence the contents of nutrients, except from Cu and Fe.The leaves collected for analysis belonged to the middle third of the plant.
The critical level of a given nutrient may be physiological or physio-economic.The first describes the relationship between the level of an element in the leaf and growth or production of the plant.The second is defined as the "level" of an element on the leaf below whose production is limited and above which fertilization is not economical (Malavolta, 2006).In addition, the leaf content is influenced by several factors that act and sometimes interact before and after the collection of leaves, such as soil, fertilization, acidity correction, family, species and variety of plant, leaf and part of leaf, as well as climate factors, cultural practices and pests and diseases.Thus, through trial and error experiments, one can establish leaf type, collection season and number of plants sampled (Malavolta, 2006).Lima et al. (2011aLima et al. ( , 2011b) ) were the pioneers to correlate nutrient leaf content with leaf position in the secondary branch (comparing also the type of branch, vegetative or floriferous), as well as variation of nutrient contents as a function of the phenological stage of the Jatropha leaf.
According to the aforementioned, as well as the lack of information about Jatropha, it is not possible to predict if a given content is adequate.
In order to obtain precise results, the studies conducted with the jatropha culture must be carried out with different parameters and stages of development, as well as in different soil conditions and management.
It can be concluded that there was no difference between mineral and organic fertilization on the initial growth of jatropha.For macronutrient contents, there was a significant difference for the P and K, only in the mineral fertilization.As for the micronutrient contents, there was a significant difference in the Mn, in the treatment with total dose of mineral fertilizer and in the treatment with 25% organic fertilizer and 75% mineral fertilizer.

Table 1 .
Height of plants of jatropha in function of planting fertilization.São Jorge do Patrocínio, PR, 2014-15

Table 4 .
Note.Means followed by the same letter in the column, do not differ by Tukey test at 5% of error probability.* and n.s.: Significant and not significant at 5% probability of error, respectively.C.V. = coefficient of variation.Micronutrient content (mg kg -1 ) in leaves of jatropha in function of planting fertilization.São Jorge do Patrocínio, PR, 2014-15