+-----------------------+--------------+-------------+----------+ | | | |Number of | | |Crop per acre.|Equivalent in|cattle fed| | | Eng. lb. | dry hay. |from each | | | | Eng. lb. |100 acres.| +-----------------------+--------------+-------------+----------+ | Pasture | -- | 1,200 | 13 | | Unirrigated meadows | -- | 2,400 | 26 | | Clover, cut twice | -- | 4,800 | 52 | | Swedish turnips | 38,500 | 10,000 | 108 | | Rye-grass | 64,000 | 18,000 | 180 | | Beet, high farming | 64,000 | 21,000 | 210 | | Indian corn, ensilage | 120,000 | 30,000 | 330 | +-----------------------+--------------+-------------+----------+ [59] I saw thermosiphons used by the market-gardeners at Worthing. They said that they found them quite satisfactory. As to the cost of heating the soil, let me mention the experiments of H. Mehner, described in _Gartenflora_, fascicules 16 and 17 of the year 1906. He considers the cost quite small, in comparison with the increased value of the crops. With £100 per _Morgen_, spent for the installation, and £10 every spring for heating, the author estimates the increase in the value of crops (earlier vegetables) at £100 every year. (Report to the German _Landwirthschafts Gesellschaft_, 1906.) [60] “Portable soil” is not the latest departure in agriculture. The last one is the watering of the soil with special liquids containing special microbes. It is a fact that chemical manures, without organic manure, seldom prove to be sufficient. On the other hand, it was discovered lately that certain microbes in the soil are a necessary condition for the growth of plants. Hence the idea of _sowing_ the beneficent microbes, which rapidly develop in the soil and fertilise it. We certainly shall soon hear more of this new method, which is experimented upon on a large scale in Germany, in order to transform peat-bogs and heavy soils into rich meadows and fields.