LAYING DOWN LAND IN FALLOW.

Otago Witness, Issue 1583, 25 March 1882, Page 6

LAYING DOWN LAND IN FALLOW.

Mr J. B. Lawes, the well-known agriculturist, has a most interesting letter in the Mark Lane Express on this subject. In a former letter, which did not come under our notice, Mr Lawes appears to have expressed the opinion that land would be poorer after two summer fallows, as he commences the letter under notice by observing that he fully anticipated being called to account for the assertion. He then observes that the beneficial effect of a fallow is due to the destruction of weeds, and the formation of nitric acid from insoluble compounds of nitrogen contained in the soil. During winter a considerable amount of this nitric acid is washed out of the soil. 'At Rothamsted,' he says, 'we have an experimental plot, which has been under alternate wheat and fallow for twenty-six years. The yield this year < was about thirteen bushels per acre ; which is almost identical with the produce of the land which has grown wheat for thirty-nine consecutive seasons, without any application of manure. The analyses of the soil of this alternate fallow and wheat land which have recently been made show a most serious decline in its fertility, and fully explain why the crop has fallen from between thirty and forty bushels per acre to its present low yield. lam quite ready to admit that a crop grown aftera two years' fallow would be larger, but this is perfectly consistent with the fact that the stock of fertility in the soil would have diminished. The object I had in view was not, however, to prove whether a fallow was or was not an exhausting process, but to urge the importance of spending less money upon tillage operations, and more upon manure when arable soil was laid down to permanent pasture. It is quite certain that arable soils are poorer than the pastures from which they are frequently derived, and that their fertility must be restored to them bof ore a fresh pasture can be said to be established. It is the cost of this operation that has given rise to the saying that "laying land down to pasture breaks a man." The question is whether some of the cost incurred cannot be saved. There is plenty of foul land in the country upon which the experiment might be made ; and I should be disposed to advise those who havo tho misfortune to own such land, at all events to try whether the superior grasses, when aided by manure, will not be competent gradually to drivo tho weeds out of the soil.'