Tillage practices and potential for no-till management in the Maltese cereal agriculture

Abstract

Wheat and barley are grown on about 45% of the agricultural surface in the Maltese Islands, and harvested as hay or straw for animal feeding. Current tillage-intensive practices contrast with those in many parts of the world, where conservation tillage has gained importance and is widespread in cereal cultivation nowadays. The objective of this study was therefore to investigate whether conservation tillage or no-till could be implemented in small-scale cereal fodder production in Malta. Indeed, the local agriculture faces several environmental challenges including soil erosion, drought and low levels of soil organic matter, which could be addressed or relieved through conservation tillage. Ten farmers and an agricultural contractor were interviewed and asked to fill in a specially designed questionnaire concerning their cultivation and tillage practices. The conclusions of the survey were then used to build an erosion model using the Water Erosion Prediction Project (WEPP): two scenarios of conventional and no-till management, respectively, were compared under Maltese soil and climate conditions. The survey reveals that the practices for cereal cultivation are very homogeneous. It was established that farmers till their soil a first time in September, and leave the land fallow until planting in November, which is accompanied by a second tillage operation. The crop is harvested between May and July, with minimum residue left on the field. The stubble is left undisturbed until September. Most of the work is performed by agricultural contractors. Comparing the conventional and no-till scenarios, the WEPP model predicts important reductions in soil erosion, especially on steeper slopes. On a monthly basis, most of the erosion is predicted to take place in the autumn months in the conventional scenario, under the combined factors of unprotected soil and intense precipitation episodes. WEPP predictions have however not shown water conservation benefits to be very significant for no-till. Runoff is predicted to be only slightly reduced, and differences in evapo-transpiration have not been investigated. In accordance to other no-till experiences worldwide, no-till is predicted to achieve similar or better economical efficiency as compared to conventional tillage. Drawbacks of no-till management would include increased herbicide usage and soil compaction. The preliminary results of this study suggest that no-till, likewise other areas in the world, could be a feasible management system in the Maltese cereal agriculture. Further studies, including field experiments and practical trials, shall confirm the potential for conservation tillage in Malta.