The work on agriculture' of Ibn-al-Awam, who lived in the 12th century A.D., treats of the varieties of soils, manuring, irrigation, ploughing, sowing, harvesting, stock, horticulture, arboriculture and plant diseases, and is a lasting record of their skill and industry.
The following passage indicates the contemporary theory of manuring: - " In thy tillage are these special opportunities to improve it, either by liming, marling, sanding, earthing, mudding, snayl-codding, mucking, chalking, pidgeons-dung, hens-dung, hogs-dung or by any other means as some by rags, some by coarse wool, by pitch marks, and tarry stuff, any oyly stuff, salt and many things more, yea indeed any thing almost that bath any liquidness, foulness, saltness or good moysture in it, is very naturall inrichment to almost any sort of land."
The first Awe work, written by James Donaldson, was printed in culture in 1697, under the title of Husbandry Anatomized; or, Scotland an Inquiry into the Present Manner of Tilling and in the 18th Manuring the Ground in Scotland.
He realized that with the enclosure of the waste lands and the absorption of small into large ho] dings, the commonfield farmer must migrate to the town or become a hired labourer; but he also realized that to feed a rapidly growing industrial population, the land must be improved by draining, marling, manuring and the use of better implements, in short by the investment of the capital which the yeoman farmer, content to feed himself and his own family, did not possess.
The average results show that, under all conditions of manuring - excepting with farmyard manure - the produce was less over the later than over the earlier periods of the experiments, an effect partly due to the seasons.
The exhaustion of the soil induced by both barley and wheat is, however, characteristically that of available nitrogen; and when, under the ordinary conditions of manuring and cropping, artificial manure is still required, nitrogenous manures are, as a rule, necessary for both crops, and, for the spring-sown barley, superphosphate also.
At the present day, thanks to the careful study of many years, the improvements of cultivation, the careful selection of seed and suitable manuring, especially with nitrate of soda, the average beet worked up contains 7% of fibre and 93% of juice, and yields in Germany 12.79% and in France 11.6% of its weight in sugar.
The roots were grown under exactly the same cultivation and conditions as a crop of mangel-wurzel - that is to say, they had the ordinary cultivation and manuring of the usual root crops.
In the case of arable soils, where the amount of phosphoric acid determined by this method falls below 01%, phosphatic manuring is essential for good crops.
Picumnus, a rustic deity (like Picus) and husband of Pomona, is specially concerned with the manuring of the soil and hence called Sterquilinus, while Pilumnus is the inventor of the pounding of grain, so named from the pestle (pi/um) used by bakers.
The composition of the tubers evidently varies according to season, soils, manuring, the variety grown, &c., but the figures cited will give a sufficiently accurate idea of it.
As a god of agriculture, especially connected with manuring the soil, he is called the son of Stercutus (from stercus, dung, a name of Saturn).
Thousands of square miles in Lower Bengal annually receive a top-dressing of virgin soil from the Himalayas, - a system of natural manuring which renders elaborate tillage a waste of labour, and defies the utmost power of over-cropping to exhaust its fertility.
With regard to the chemical composition of the ripe grain, the Rothamsted experiments reveal a singular uniformity, even under very varied conditions of manuring, and even where much diversity was apparent in the constitution of the straw.
It has also been observed that too heavy nitrogenous manuring stimulates and prolongs the growing period of the wheat; flowering is retarded, and thus there is a greater opportunity for infection to take place.
It is true that on the continent extracted meal, especially rape meal from good Indian seed and palm kernel meal, are somewhat largely used as focd for cattle in admixture with press cakes, but in England no extracted meal is used for feeding cattle, but finds its proper use in manuring the land.
The height of the plant varies greatly with season, soil and manuring; in some districts it varies from 3 to 8 ft., but in the Piedmont province it is not unusual to see them from 8 to 16 ft.
The cost of planting and the outlay for manuring and weeding during the years of maturity of the crop, are higher in the Midlands and the yield was estimated by Ellmore at 6 to 10 tons per acre, green, worth from £3, ios.
If one condition is more necessary than another for good crops it is a suitable supply of water, for no amount of manuring or other treatment of the soil will make up for a deficient rainfall.
Lime also assists in the decomposition of the organic matter or humus in the soil and promotes nitrification; hence it is of great value after green manuring or where the land contains much humus from the addition of bulky manures such as farm-yard dung.
But it gave some impetus to the practice of green manuring with leguminous crops, which are equally capable with such a crop as mustard of enriching the soil in humus, whilst in addition they bring into the soil from the atmosphere a quantity of nitrogen available for the use of subsequent crops of any kind.