One of the chief problems in market gardening in the open and under glass is the supply of humus. The introduction of the internal combustion engine changed this: a general shortage of manure resulted. In most cases market gardens are not run in connection with large mixed farms, so there is no possibility of making these areas self-supporting as regards manure: the essential animals do not exist.
The result is that an increasing proportion of the vegetables sold in the cities is raised on artificial manure. In this way a satisfactory yield is possible, but in taste, quality, and keeping properties the product is markedly inferior to the vegetables raised on farm-yard manure. It is an easy matter to distinguish vegetables raised on NPK. They are tough, leathery, and fibrous: they also lack taste. In marked contrast those grown with humus are tender, brittle, and possess abundant flavour. In the first place, market gardening should, whenever possible, be conducted as a branch of mixed farming with an adequate head of live stock, so that all the waste products, vegetable and animal, of the entire holding can be converted into humus.
To this end the estate has been developed as a complete agricultural unit with a proper proportion of live stock, arable land, grass land and horticulture, with the belief that after a few years of proper management the estate can become very nearly, if not entirely, a self-supporting unit, independent of outside supplies of chemical manures, and feeding stuffs, the land being kept in a high state of fertility, wh