CHAPTER ONE
INTRODUCTION
Background to the study
One of the aboitic challenges facing crop production in the Tropics is the inherent low concentration of essential nutrients in the soil for crop growth and development (Schlecht et al., 2007). Essential nutrients are those nutrients which are required by plants to complete their life cycle such as Nitrogen (N), phosphorous (P), potassium (K) often referred to as primary nutrients, calcium (Ca), magnesium (Mg) and sulphur (S) called secondary nutrients and Boron (B), Chlorine (Cl), copper(Cu), manganese (Mn), Iron (Fe), molybdenum (Mb) and Zinc (Zn) called micronutrients (Barker and Pilbeam, 2007). These nutrients can be provided to the soil through the use of fertilizers. Fertilizer can be in organic or inorganic form. The use of inorganic fertilizers has not been helpful as it is associated with increased soil acidity, leaching and nutrient imbalance (Schlecht et al., 2007). According to Ayoola and Makinde (2006) inorganic fertilizers are usually not available and are always rather expensive for the low-income, small scale farmers. Organic manure such as cow-dung, poultry manure, swine waste, sewage sludge, crop residue can be used as an alternative for inorganic fertilizer. The nutrient contained in organic manure is released more slowly and are stored for a long time. Manure application also increase soil porosity and aggregate stability, promotes soil water infiltration and holding capacity, elevates soil organic matter content, soil pH, cation exchange capacity and nutrient availability (Powell et al., 1996; 1999;Powell and Unger, 1998).
However, the main defect in the use of organic nutrient source in crop production is the limited supply (amount) and bulkiness of organic materials. Composting is a management practice to improve manure efficiency or quality. Well managed compost has good agronomic properties such as good water holding capacity, light weight, small particle size. It is cheap and can easily supply nutrients to the crop (Miller and Norman, 1992).
Cucumber (Cucumis sativus L.) is a vegetable crop eaten by most families in the Tropics. It is one of the most popular members of the Cucurbitaceae (vine crop) family. It is cultivated for fresh fruit which is locally consumed or exported to increase national income. The crop is cultivated in most parts of Northern Nigeria and some parts of Eastern Nigeria by peaseant farmers who lack information on some important cultural practices (Ekwu et al., 2007). Cucumber is a vital ingredient in vegetable salad in human nutrition. The fruit varies in shape, size and color. On analysis, mature fruit nutrient composition is 3.8 g dry matter, 0.6 g protein, 2.0 mg calcium, 0.4 mg riboflavin, 0.2 mg niacin and 11 mg vitamin. The fruit also serves as remedy in the treatment of constipation, jaundice and indigestion (Chadha, 2006).