The investigations to be described below are the outcome of some experiments started in 1900 which had in view the improvement of English-grown wheat. The necessity of such work may not be evident to all, so at the outset I will sketch in broad outlines the state of affairs which led me to undertake the task. The fact is generally recognized that the wheats of this country are characterized by their high yields per acre and by the shapeliness of their grain. We can grow on the average over 30 bushels to the acre where the United States grow 14, Russia 10, and the Argentine 7. Yet the acreage under wheat in this country has fallen from three and a-half million acres in 1876 to one and a-half million in 1903, and we now grow approximately only one-fifth of the wheat we consume. Further than this there is good evidence to show that the quality of the grain now grown is inferior to that of twenty years ago. It has been sacrificed to yield, and many of the better class varieties, such as Chiddam, Red Lammas and Rough Chaff, have been more or less driven out of the field by varieties such as Square Head and Rivet, which are capable of giving slightly larger crops of grain and straw. These inferior varieties have now to compete with wheat imported from Canada, the United States, Russia and other countries. The seriousness of the position becomes evident when one finds English wheat selling at 28s. 6d. a quarter when Manitoba Hard is selling at 35s.

In general the hop is diœcious. Sometimes, however, in gardens of the Bramling variety, hills are met with from which bines arise bearing both male and female flowers. Such monœcious plants are rare.

For nearly eighteen years the problem of the fixation of nitrogen by the root nodules of leguminous plants has been the subject of investigation by numbers of workers in many parts of the world, and steady progress has been made towards realising the conditions under which the organism works in the nodule. Artificial nutrient media have been prepared closely resembling the food supplied by the plant, and the organism itself has in recent years been induced to grow in artificial culture in the characteristic “bacteroid” forms approximating to those which are found in nature.

One of the main problems placed before the agricultural chemist is the estimation of the requirements of a given soil for specific manures, or the interpretation, by means of data obtained in the laboratory, of the behaviour of the soil towards these manures, as seen in properly arranged field experiments. For various reasons the obvious method of determining the proportions of Nitrogen, Phosphoric Acid, and Potash in the soil fails in many cases to give the required information; even the more modern methods of measuring only the quantities of these materials which are attacked by weak acid solvents, and in consequence regarded as available to the plant, by no means always accord with the results of experience. Hence from time to time attempts have been made to attack the problem from another side and to use the living plant as an analytical agent. The scheme is to take a particular plant grown upon the soil in question, and determine in its ash the proportions of constituents like phosphoric acid and potash. Any deviations from the normal in these proportions may then be taken as indicating deficiency or excess of the same constituent in the soil and therefore the need or otherwise of specific manuring in that direction. The theory rests on two assumptions, first that each plant has a typical ash composition, constant when the plant is grown under similar conditions; secondly that the variations in the proportion of such a constituent as phosphoric acid will reflect the amount of that plant food available in the soil, as measured by the response of the crop to phosphatic manuring. From this point of view a number of investigations have already been made: Hellriegel discussed the relative variations of the proportion of potash in the ash of barley straw and of the soil in which it was grown; Heinrich analysed the roots of oats and fixed certain minima, below which the need for specific manuring was indicated.

That swedes are better feeding materials under some conditions than under others is more or less generally recognised; the suggestion of controlling these conditions is perhaps not new, but little of practical importance has been achieved in this direction. About five years ago the subject was considered at the Durham College of Science (now Armstrong College), Newcastle-upon-Tyne, and experiments were started which have been repeated and added to every season. The object of these investigations was to form a list of the different varieties of swedes in order of merit. Incidentally other points of interest have arisen, and are dealt with in the following pages. The results of these experiments have been published each year in the Annual Report of the Agricultural Department of the College, but a review of the work done seems of sufficient general importance to prove interesting to a larger circle of readers.

The use of town stable manure enters so largely into the economy of farms, and especially market-gardens, situated within fairly easy distance of London or other large cities, that it is somewhat curious that but little information has been published in this country as to its chemical composition. In fact, with the exception of a couple of analyses made by myself as long ago as 1889, which were published at the time in the Mark Lane Express, and subsequently reprinted in Aikman's book on “Manures and Manuring,” I do not remember to have seen any analyses of London manure. The samples which were the subject of these analyses were collected from a very limited number of stables, some of which were littered with peat moss and others with straw, the object at the moment being to compare the manure produced with the two kinds of litter. I have more recently however made some fairly full analyses of two more representative samples of London manure, but before proceeding to give these it may be desirable to reprint in this place, for future reference, the old analyses just mentioned.

Summarising the above comparisons between soil analyses and results of manuring, the following conclusions are arrived at:

That except in extreme cases the determination of the percentages of “total” nitrogen, phosphoric acid, potash, and lime, in a soil does not give reliable indications as to the possibility of improving the pasture by manuring.

That determination of the percentage of phosphoric acid soluble in 1 per cent, citric acid solution does generally give reliable indications as to the probable success of phosphatic manuring, provided that for pasture soils the limit below which “available“ phosphoric acid may be considered as deficient is fixed as high as 0·02 per cent.

That potash manuring is suggested as likely to give distinct results if the soil contains not more than 0·01 per cent, of potash soluble in 1 per cent, citric acid solution.

That liming is not indicated as likely to be profitable unless the soil contains certainly less than 0·25 per cent, of chalk.

1. The results of six experiments in the manuring of poor pastures are described. The experiments were made in the counties of Northumberland, Northampton, Cambridge, Essex, Norfolk, and Hants. The results are given for a period of three years at all stations (except Norfolk, two years), and for two further periods of three and two years at the Northumberland station.

2. In Norfolk on a light soil a potash manure slightly improved the pasture; the other manures had no influence on the yield. At the remaining five stations on heavy soils phosphatic manures produced highly profitable returns. In the first period, the use of other manures was not justified by the results. Where, however, the experiment was continued for eight years, lime proved profitable in the second, and potash in the third period. Under the special conditions of the experiment nitrogenous manures were either injurious or but very slightly increased the yield.