EVERGREEN AGRICULTURE
Introduction
In Malawi, agriculture dominates the economy contributing 37% of GDP. Over 80% of the population is practicing smallholder agriculture which is characterized by ridge based tillage and burning of residue. Over 70% of smallholder farmer agriculture in Malawi is dominated by
conventional tillage. Ridge construction is the cornerstone of conventional agriculture in Malawi. This construes the annual construction of ridges, burning of crop residues and monocropping in most areas of Malawi. Conventional tillage practices involve several operations in the preparation and maintenance of a seedbed suitable for seedling emergence and crop growth and development.
Advantages of Ridge Tillage
The ridge tillage involves inverting, cutting or shattering the soil to a depth of 15-36cm and usually this leaves the soil rough. This tillage is called primary tillage. The purpose of primary tillage include loosening and aerating the surface layer of soil, incorporating fertilizer, and mixing plant residues into the surface layer of soil. Secondary tillage prepares a final seedbed suitable for planting seed and its subsequent germination, seedling establishment and weed control. This type of tillage was mandated by colonial government through the department of agriculture as a recommended land husbandry practice in Malawi. It was proven that the local farming practices predisposed the agricultural land to heavy soil erosion and degradation and are responsible for low crop productivity. As a result, the colonial government vigorously reinforced the construction of a variety of ridges on smallholder farmer‟s crop field which ranged from tie box ridges, contour ridges, contour bunds to planting ridges. This extension system further encouraged residue burning and monocropping for clean agriculture. This hardly changed when Malawi became independent of the British rule duringthe Kamuzu Banda era. Consequently the crop field soils have undergone decades and decades of “splitting and reforming” every year.
Disadvantages of Ridge Tillage
This type of tillage practice causes the following effects; soil exposure, run off, erosion, oxidation of organic carbon etc. The effects are causative agents for poor soil health in Malawi. Nonetheless, the chemical fertilizer application has not reversed the soil health situation but has to some extent aggravated the sore conditions of the soils under smallholder agriculture. However, it is also worth noting to see how the farmers have religiously been following this tough and wearing out farming practice for many decades. This practice requires farmers to be splitting the ridges to form another ridges every year. Nearly 3 million smallholders tend to split and reform ridges before the planting rains. Surprisingly this practice appears to have gone unquestioned by just about every „expert‟ connected with small-scale agriculture over the past 60 years.
