“Direto no Cerrado”

The publication of the Association of Direct Drilling in the Cerrado (APDC)

http://www.apdc.com.br

Year 10, No. 40, February/March 2005, page 3.

“Sorghum, an alternative soil cover for the consolidation of direct drilling in West Bahia”

Author: Ingbert Döwich, specialist in direct drilling in Luís Eduardo Magalhães, Bahia.

The trial of soil cover crop alternatives with a view to crop rotation and dry matter production for the direct drilling system was conducted in two consecutive years in collaboration with the Direct Drilling Club (DDC), together with the Ministry of the Environment, the Association of Direct Drilling in the Cerrado, the Rural Union, Embrapa, rural producers and other collaborators. The demand for alternatives for the rainy and post-rains seasons has grown as a result of farmers’ needs to: lessen the impact of monoculture (soybean and/or maize and/or cotton), reduce production costs, increase income, protect the soil between harvests, create opportunities for crop-livestock integration and to maximize the use of climatic factors with a higher yield and, concomitantly, environmental preservation.

From results obtained with the alternatives trial, sorghum was selected as the option for further studies. A proposal for cooperation in diffusion of technologies was made with the sorghum seed companies for the 2003/2004 season and the cultivar comparison trial under dry direct drilling was established in West Bahia, which offers a high physical variability. However, for every specific situation and over time, social, economical and geographical contexts, humans have somehow adapted their activities - especially those concerning the agricultural sector - and with the objective to increase the economic crop productivity.

Sorghum is a relatively marginalized crop in the different regions. Brazil has the most diverse production systems and due to the great environmental heterogeneity there’s a need to publicize the crop technology and develop cultivars adapted to the different conditions. The choice of cultivars adapted to regional or local conditions can represent substantial gains in the final production.

The objective of the trial was to identify and select the cultivars most adapted to the edapho-climatic conditions of the region. The repetition of these trials for various years in a same region allows the evaluation of hybrid stability and the testing of new cultivars that are introduced to the market every year. We therefore intend to offer alternatives for crop rotation and for potential dry material production for the direct drilling system, looking after the needs of associate DDC farmers and of the Rural Union, reaching an expressive number of rural companies in West Bahia.

The fertilizer and cultivation management strategies were in accord with those recommended by the Ministry as were the machines needed for the installation of the experiments. The supervision was under the responsible DDC technician in each experiment. The trial plots were established in strips equivalent to two widths of a soybean drill over the length of the area with three replications. Weeds were controlled with 1,2 l/ha of atrazine at the pre-emergence stage; there was no pest or disease control. The results are expressed in the following figure:

Figure: Dry matter (yellow) and grain (red) production in kg/ha of different commercial sorghum cultivars. Döwich, I. and Fischer, E.C. From 2004 demonstration sample plots.

They best biomass production of  >8 000 kg/ha was obtained with the cultivar ‘IPA 1011’ with a grain yield of >3 000 kg/ha. Other cultivars of note were DOW 740 and AG2005-E (about 5 000 kg/ha of biomass).

Therefore one concludes that sorghum cultivation shows a high biomass and grain productivity, which makes the crop important in the consolidation of the Direct Drilling System in the West Bahian Cerrados.