GREEN MANURING.

Dominion, Volume 4, Issue 1234, 16 September 1911, Page 8

GREEN MANURING.

FOB SOIL RENOVATION PURPOSES. 11l an interesting article 011 green manuring, Mr. A, ii. "Wood, Agricultural Chemist, says:— "How a soil can bo enriched by green manuring is not too well known, Ivitrogen, the most expensive plant food, can bo conveyed to the soil at a cost l'ar cheaper than applying it through tho medium now practised. I will just givo an example. If a leguminous crop 6uch as clover is ploughed ir- just as the clover arrives at maturity, tho soil receives a manuring to tho extent of 1001b. of nitrogen per acre, in other words, tho soil 'lias been supplied with nitrogen from this source,- which, if supplied by the commercial nitrogenous manures now in use, would require Blcwt. bload or 'lewt. ammonia sulphate to equal tho amount of nitrogen gained by tho system of green mama-ins;. I am not allowing anything for tho humus, which, of course, is produced at tho same time. The benefit upon clay soils is beyond estimation. I particularly mention clay soils, for it is this class of country that so needs nitrogen in. conjunction with humus. The best crop for this purpose can be selected by tho farmer, l'he quickest matured will bs the best—those most suited to the dis-. trict. Peas, clovers vo'ches, lucerne, lupins are a few of the most useful ones. The cost of seed may bo heavy, but the great benefit derived in every case will repay the outlay. An experiment' was carried out by tho Agricultural Department. and in this case vetches were selected. Tho report runs .as follows:— Vetches at Ruakura. "An experiment farm demonstration which has served a valuable purpose in the immediate district is that in connection with vetches at the Ruakura Farm of tue Department. Vetches were grown 011. an extensive scale, with the object of .providing early spring feeding both for ewes and Jambs, also as a soiling crop for dairy. cows, and again for ploughing in wnere tho soil was deficient in liumns, the vetches being a deep rooting and highly nitrogenous plant. Tho efficacy of vetches for the two former purposes appealed at onco to th) farmers of the district, mid they are becoming quite a feature of local farming operations. This dry season vetches have proved' an excellent stand-by at Ruakura; and after. close feeding down on two occasions have now provided a good wealth of material for ploughing in, to thereby improvo the soil texture. ■ ' ,

"Atltuakura the land used for the experiment, in an oat crop tho previous season, was ploughed and left fallow for a few, mouths. ,Tho field had become foul through excessive cropping, and it was necessary in consequence to again plough in May. Tho land was disced twice, tineharrowed four times, nnd rolled. The seed was sown with Slcwt. manure, ljcwt. super, and lewt. bonedust to the acre in June, and the land was again rolled. In September tho crop had made a vigorous growth of about 18in. in height. Ewes and lambs were then turned on to it, 150 on to tho three acres. This stocking was maintained for a fortnight, both tho ewes and lambs having rapidly improved in condition during that p'eriod. After two .weeks', rest tho field was as luxuriant in growth,as before. Again the same number of ew;s and lambs were .turned on for n fortnight. When tho field had been rested for several weeks, the crop had onco more regained its former development. From the middle of November to well on into January the field carried eighty, wpaned lamb?, which finished prime, with tho crop by no means eaten down. Subsequently the crop was ploughed under.

Another crop on an adjoining field, which-had not been grazed, was cut and carted out- to the dairy stock and working stock in the beginning of the year, five acres lasting for .six weeks, and-this during the driest months of the season. Then, as with tho main crop, it was ploughed under,-and the paddocks sown on May •1. At the present time tho vetches are showing up : thickly with the grass, tho wholo forming a. luxuriant pasture, giving evti-jr -promise' of providing excellent spring feeding," A Valuable Fodder Plant. Farmers in other districts would find the vetch a valuable fodder plant, as it thrives well in dry seasons,' is not susceptible to blight, and,. given fair treatment, will provide at tho least twentyfour tous of green fodder to the acre. It is.easy of cultivation. Like all other .crops, of course, if a good yield is to be 'secured,. a good seed, bed must bo. provided. It is one of tho best soil renovators we have, ris the vetch gives a great wealth of material with little manuring; it is one of tho most valuable of ail crops for ploughing in on light land. It may Ire considered that as tho seed is apparently expensive the vetch is not an economica'l crop. When, however, it is remembered that even if the seed costs 10s. 6(1. a bushel, only a bushel aud a half is required to tho acre, a great wealth of green fodder is provided'(which may-be eaten down several times even in a dry season), that it requires little manure, is ■easy to grow, is not affected by blight, and when finished with for feeding purposes, provides excellent material for ploughing in to enrich tho soil, tho net result- will. lie seen to considerably counter-balance any excejjiional first cos't for seed. In this connection tho wisdom is suggested of the farmer threshing sufficient of his crop to provide his- own seed. .

"The necessity of nitrogen being available," Hγ. Wood adds, "needs little comment—on the other hand vory careful consideration must bo taken when such a costly plant food is wanted—which is the cheaper lvay to obtain same, should demand the farmers' attention. In the early portion of this, article I pointed out that clorer ploughed in would provide 10011). nitrogen' to tha soil per acre. Against this let us place the amount of nitrogen removed by a feiv of our crops —the -average composition of crops mostly grown locally, 2-1 ton crop per acre of turnips, including roots and leaves, re-, move 2211b. of nitrogen per acre; an oat crop weighing -15 bushels, plus tho straw, removes 5511). nitrogen; 45 bushel wheatcrop, including straw, takes 721b.; 3-ton per acre of hay, 981b.; 12 tons per aero of potatoes remove 911b. Of course, these figures, showing the removal of nitrogen, 'may bs considerably lower according to the farming system adopted—a lesser quantity is removed .when stock are fed in, paddocks, where straw is consumed upon the paddock, etc. Tho above figures are based upon actual removal from farm. The figures are abstracted from tho findings of. tho most distinguished chemists: Sir .T. B. Lawes. Sir J. Henry Gilbert, and Dr. Vocleker. Farmers who wish trrenovate their soil should remember that it will pay to turn under a leguminous crop—although it may seem hard to so quickly lose- from sight n green crop— beneficial effects will ultimately take place."