Setting up and monitoring research on simplified cultural techniques for large-scale motorised farming on the clayplains of Pandamatenga, Botswana : Consultancy mission by the Annual Crops Department. Mission from 27 November to 16 December 2000

This document reports the findings of a brief mission of which the main objective was to make a proposal for a long term field trial on cultural practices, especially those which involve the implements that should be used, in order to increase the production level per unit area and net income of the large scale farmers in the clay plains of Pandamatenga and to identify systems which preserve in the long term the production potential of the soils. The study was carried out by the department of annual crops of CIRAD, the French centre for international Cooperation in agronomic research for the development of tropical and subtropical regions, with the financial help of the French ministry of foreign affairs at the request of the Botswana Ministry of Agriculture to help its department of agricultural research (DAR) in the above mentioned topic. A field trial has been proposed to DAR. It should be implemented during the 2000/01 cropping season. It will occupy an area of 14.5 ha and has three main treatments which compare conventional tillage to no till on flat land and the two to no till on broad permanent beds with controlled field traffic. Each treatment is split in two sub treatments. It is a longterm trial for a three-year crop rotation of sorghum, sunflower and cowpea set up so that every year all the crops are grown in the trial. Monitoring of the trial is extensively developed in the report (see § 5.2.2.) and an English version was sent to DAR mid December. The same trial should also be implemented on Masedi farm and a similar trial is proposed for the sorghum, cotton, sunflower rotation. In Chapter 7, training is proposed in four fields [soil chemistry, soil physics, agro-meteorologic and (no)till practices] for local personnel. For those concerned by soil physics and no or minimal tillage practices, the chosen people should live at Pandamatenga during the cropping season and for at least one crop rotation. A follow up of the monitoring, as well as data collection and interpretation and implementation of other trials aimed at restoring the physical fertility of the soils damaged by field traffic under bed conditions, will be necessary and done by a senior expert in soil mapping, soil physics and mechanics as well as in tillage practices. In the report, other recommendations are done to DAR and more generally to the Ministry in order to increase yields and farmers revenue per ha. Between these recommendations we mention here the need for: - the establishment of more detailed soil and topographic maps; - locating the meteorological station at a more representative site, i.e. in the clay plain instead of near the wooded sandveld; - the acquisition by the substation of equipment permitting subsoiling and flat broad bed cultivation as well as an oven for determination of gravimetric water content and a rubber balloon density meter for bulk density measurements on a per liter basis. (Résumé d'auteur)