RESEARCH AND EXTENSION NEEDS TO MITIGATE CONSTRAINTS LIMITING THE PRODUCTIVITY OF SMALL-SCALE SUGARCANE FARMERS IN MAURITIUS

Abstract The issue of low productivity on small farmers' lands is a matter of concern in many sugarcane producing countries. In Mauritius, some 25 000 small-scale farmers are involved in sugarcane cultivation which is a major source of income for 200 000 rural families. Yield differences as high as 40% exist between the small-scale and large commercial farmers and their causes are often taken for granted. This paper presents part of the findings of a project to better understand, with farmers' participation, the functioning of the existing small farming systems and their information-seeking behaviours, a study financed by the French government through the Southern African Development Community (SADC). A survey, based on a formal questionnaire, was carried out among 800 farmers in Mauritius. Analysis of the data collected has enabled the prioritisation of factors and constraints affecting productivity, namely, increasing costs of inputs, availability and costs of labour and transport and access to finance and credit facilities. The conditions limiting adoption of good management practices have been identified to be the small-sized farms, low adoption rate of improved technologies and limited contact with advisory and support services. The elaboration of decision support tools to assist these farmers to increase production levels through sustainable and environment friendly production systems will now be generated. There is a need to pursue specific research on cost-cutting farming operations and new production techniques, adopting extension strategies favouring targeted and grouped extension interventions for some categories of small-scale sugarcane farmers. It is believed that the research and extension interventions will ensure the long-term survival of this producer category and will enhance ability to achieve productivity levels that will render the agricultural activities of the small-farmers economically and environmentally sustainable

Leaching of nitrogen, potassium, calcium and magnesium in a sandy soil cultivated with sugarcane Lixiviação de nitrogênio, potássio, cálcio e magnésio em solo arenoso cultivado com cana-de-açúcar

A lysimeter experiment was carried out with sugarcane aiming to evaluate the leaching of nitrogen derived from either urea (15N) or the soil/sugarcane crop residues. The leaching of K+, Ca2+, and Mg2+ was also evaluated. The experiment was a factorial 2x4. The influencing factors were: firstly, the differential addition of two kinds of sugarcane remains to the soil, simulating conditions of cane- plantation renewal after the cane crop harvest, with and without previous straw removal by burning; secondly, four doses of N: 0, 30, 60, and 90 kg ha-1. During the experimental period the total volume of water received by the sugarcane-soil system was 2,015 mm, with 1,255 mm as precipitation and 760 mm as irrigation. The loss of N by leaching from the fertilizer (15N) was not detected. In the first three weeks the largest losses of N by leaching occurred, originating from the soil/sugarcane remains-N. The mean of leached N during the experimental period of 11 months was of 4.5 kg ha-1. The mean losses of K+, Ca2+, and Mg2+ were of 13, 320 and 80 kg ha-1, respectively.<br>Realizou-se um experimento em lisímetro cultivado com cana-de-açúcar para avaliar a lixiviação do N, oriundo da uréia (15N) ou do solo e de restos culturais, bem como do K+, Ca2+e Mg2+. O experimento foi um fatorial 2x4. Os fatores foram: 1) adição diferenciada de dois tipos de restos culturais ao solo, simulando condições de reforma de canavial após a colheita da cana, com ou sem prévia despalha a fogo; 2) quatro doses de N: 0, 30, 60 e 90 kg ha-1. Durante o período experimental o volume total de água recebido pela cultura foi de 2.015 mm, sendo 1.255 mm de precipitações e 760 mm de irrigações. Não foi verificada perda por lixiviação do N derivado do fertilizante (15N). Nas três primeiras semanas ocorreram as maiores perdas de N por lixiviação que foram provenientes do solo ou dos restos culturais. O valor médio do N lixiviado durante o período experimental de 11 meses foi de 4,5 kg ha-1. Os valores médios de perdas de K+, Ca2+ e Mg2+ foram de 13, 320 e 80 kg ha-1, respectivamente