SOIL NUTRIENT STATUS OF SMALLHOLDER FARMS IN MALAWI

A soil sampling exercise was conducted throughout 60% of the smallhold er farm sector of Malawi, a small country located at the base of the G reat Rift Valley. Soil samples (1,130) were gee-referenced and analyze d for pH, texture, soil organic carbon (C), phosphorus (P), zinc (Zn), potassium (K), and calcium (Ca) status. Descriptive statistics of soi l characteristics were used to evaluate soil fertility for two agricul tural districts in Northern Malawi, two agricultural districts in Cent ral Malawi, and one agricultural district in Southern Malawi. Generall y soils were loamy sands and moderately acid, With ''low'' to ''suffic ient'' nutrient levels. Over three-quarters of soils sampled had organ ic C levels which were greater than 0.8%. This indicated that organic C status was adequate in the main to maintain soil structure, although much reduced from the non-cultivated state. The organic C data suppor ted observations of widespread nitrogen (N) deficiency in Malawi. High spatial variability of P and Zn values was noted. However, over 60% o f soils had a P status above the critical value of 15 mg kg(-1) which was sufficient for smallholder maize production levels. This finding s upported efforts to alter the current country-wide fertilizer recommen dation of 45 kg ha(-1) phosphate. New findings reported here were loca tion specific edaphic problems: i) widespread moderate soil acidity in Central Malawi, ii) natural regions in Central and Southern Malawi wh ich were low in P and Zn, and iii) natural regions in Southern Malawi were very low in organic C. Research requirements were identified. Sug gested priorities for technology development were those appropriate to smallholder farmers, such as combined use of small amounts of inorgan ic and organic fertilizers to address very nutrient deficient soils.