Consórcio de pinhão-manso com espécies forrageiras e produtoras de grãos

Abstract

Considering Brazil’s potential to become one of the biggest biodiesel worldwide producers, and the fast expansion of the global demand for biofuels, due to the concern with reducing emissions of greenhouse gases, since it is a case of an untamed species and without many studies and technologies, there is a need of researching to consolidate this new model. With the aim of reaching these results, this paper evaluated the grain yield and Jatropha curcas L. oil and different kinds of forages and grain producer, grown between the rows of Jatropha curcas L., and also, the soil chemical attributes depending on the treatments. The design was conducted in the experimental plot at Embrapa Agricultural West, in partnership with Paraíso Farm, located at coordinates 22º 05’ 44’’ S and 55º 18’ 48’’ W, in the District of Itahum, Dourados, in an area of Dystrophic Red Latosoil, soils with an average of 200 g kg-1 clay. The Jatropha curcas L. was first introduced in November 2006, through tillage system, carried out in the 3 x 2 m spacing, leaving one plant/burrow. During the crops of 2006/07 and 2007/08, it was carried out the conduction and crops treatments, generally used for the crop. The experimental plots were made by four rows with six plants per row. The treatments were: (T1: Jatropha curcas L. didn’t have any grown species between the rows (single Jatropha curcas L.); T2: estilosantes-campo-grande (Stylosanthes spp.); T3: brachiariaruziziensis (Brachiaria ruziziensis); T4: Brachiaria-ruziziensis + estilosantes-campogrande; T5: brachiaria-humidicola (Brachiaria-humidicola); T6: grass-massai (Panicum maximum cv. Massai); T7: rotation system 1 (peanut–crambe–beans-corn); T8: guanduanão (Cajanus cajan); T9: crotalaria (Crotalaria spectabilis); T10: rotation system 2 ( season corn-crambe-soybeans-peanut) and T11: rotation system 3 (caupi-beans – turnipcorn- caupi-beans). Each treatment had a parcel with a single crop where Jatropha curcas L. didn’t have any grown species between the rows (single Jatropha curcas L.). The treatments started in the agricultural year of 2009 with the spacing and sowing density specific to each species. The weight of a hundred grains, the grain yield and the Jatropha curcas L. oil yield weren’t influenced by the treatments between rows. The total oil content in the seeds of Jatropha curcas L.was influenced by treatments. The plants height, the canopy diameter, the log diameter and the number of main branches of Jatropha curcas L. didn’t have any kind of influence by treatments. In an average, the 2009/2010 crop had the maximum plants height, canopy diameter, the log diameter and number of branches. The intercropped species didn’t influence the development and the indexes of Jatropha curcas L. production. Thus, the Jatropha curcas L. growing can be grown intercropped with all the studied species. The dry matter yield and the average plants height, from the different species intercropped with Jatropha curcas L., showed a response among species and cropping systems. Comparing the systems, in the average of the studied species, the intercropped sowing had a greater plants height. The intercropped sowing system also provided the lowest seasonal dry matter yield in the intercropping. Observing the matter production during the year, in both cropping systems, it’s clear the smallest change, especially between July/09 and March/2010, for the intercropped system. This behavior may be linked to the interaction among the cover plants and Jatropha curcas L., that with the leaves falling and decomposition during fall/winter, may be contributing to maintain the soil moisture and improve its chemical and biological conditions. The species that showed a better adaptation to the intercropped sowing between the rows of Jatropha curcas L. growing was massai-grass, showing higher dry matter production. However, all the studied species had agronomic performance to be used as soil covering or forage, regardless to the growing system, in Dourados-MS. The caupi-beans crops tested during 2008/09 and 2009/10 season crop showed satisfactory yield when sowed intercropped with Jatropha curcas L.; thus, they can be grown in this growing system. The BRS 1010 corn crop had better results in the intercropped system during 2009 season crop and BRS 106 during 2010 one. The turnip crops had satisfactory yield in the intercropped sowing system, being the same ones indicated to the Jatropha curcas L. crop between rows. In 2009/10 crop, the corn and soybeans showed a very low yield; so, they didn’t adapt themselves to the intercropping, during the crop, of these species intercropped with Jatropha curcas L. that was 3 years old, when it was used the 3 x 2 spacing for the Jatropha curcas L.. The soil plants cover and rotation systems were tested and contributed to the improvement of soil fertility. The P and K elements were the most affected by the rotation systems with yearly crop. Ca and Mg elements were the most affected by forage crop. In the system where Jatropha curcas L. didn’t have any grown species between the rows (single Jatropha curcas L.), the intercropped system (single Jatropha curcas L.) had higher levels of organic matter and phosphorus regarding to that trial of single cropping system (total fallow).