ABSTRACT
Soil is the gardener’s most precious natural asset requiring understanding and nurturing. Developing and maintaining soil fertility, health, quality and tilth are primary requirements for a productive garden. These are initially achieved by the basic practical practice of digging which is the first step in cultivation permitting the incorporation of organic materials and the burying of annual weeds. Best practice in the physical processes of manure or compost incorporation and the inversion of soil are illustrated and described. This is followed by adjusting where necessary, the soil pH by liming which encourages the release of nutrient for subsequent plant growth. Dug land requires weathering by frosting and other physical, chemical and biological processes which help develop a friable crumb structure suitable for crop production.
Techniques for managing and using well-prepared soil for potato and bulb onion crops are illustrated in detail. The text explains how potatoes and onion bulbs are selected. Potato varieties differ in their season of maturity depending on the length of time required for the initiation and subsequent growth of tubers. Maturity classes are grouped as: early, mid-season (second-early) and late varieties. Once selected, the tubers are encouraged to produce sprouts (chitting) before being planted. Land preparation, planting processes and subsequent husbandry are described. Onion bulbs may be planted directly into the garden or their maturity accelerated by encouraging early growth in a greenhouse. Planting of onion bulbs and plants is illustrated followed by suitable crop care. Weed control is essential for onion crops and disease limitation may be necessary for potatoes.
Understanding how fertile soils can be developed requires knowledge of the processes by which they form naturally. These topics are explained together with descriptions of soil profiles, structure, texture and composition for mineral and organic soils. Dangers of soil erosion by water and wind are emphasised. Soils are living entities containing a vast range and number of bacteria and fungi. Most are highly beneficial for the garden by helping to increase nutrient availability and repel some of the deleterious disease-causing microbes. Also present are macro-organisms which also vary between beneficial and harmful types.
Fuller understanding of soil and its composition and properties is gained by handling it. This is achieved by finger tests of soil structure, observing the segmentation of constituents by flotation tests and manually exploring soil profiles. Profiling may also be achieved using augers and the types available are illustrated. Testing soil acidity and alkalinity by means of pH probes and kits is an essential part of soil care and is necessary for the production of successful garden crops. Explanations of pH determination and the types of fertiliser available for supplementing soil reserves are given along with suggestions for professional soil sampling. Learning achievements are listed at the end of the chapter.
