GREEN MANURING

Hawke's Bay Herald-Tribune, Issue 134, 23 June 1937, Page 15

GREEN MANURING

Increasing Organic Matter in Soil Green manuring consists of ploughing ujider green crops for tlip benefit of the soil, Thp practice resujts in increasing the organip matter in tlie soil, If iegumes are used for this purpose the uitrogen content of the soil may also be increased. Freferenep Bhould be given to Iegumes for this reason, 'Php ehoice pf a .Cj-pp fpr green manuring purposes will" depend upon n uumbej* of factors. Other things bpipg equal, deep-rpoted props are preferable to thpse havjng sijaljpw rppt syitems. Plants with deep roots gather some mineral constituents from the eubsoil, and upon decay of the plants leave them in the surfaee in an oragnic form., Deep-rooted plants are also heneflcial beeause they improve the physical condition of the subsoil. In general crops that will furnisb the largest aniounts of humus and nitrogen-j'earing mator ial for the soil should be selected. The principal crops used for green manuring are lpcerne, clpvers, cow peas, field peap, soy and other bepus, and vetch. These are aU Iegumes under most conditions where gjreen pastures can be used. On poor soils lime and minpral fertiliperp may be used with prqfit in the production of a green manure crop. Tliis will stjmnlate thp crop to greater growth,. and Avhen it decays in tfie sojl tbo elenients applied >vill again become available for the prop that is tp follow. Ihe composition of the Iegumes used lor green manufing varies eonsjderably, depeuding npon local conditions, charaeter of soil, and the stago of maturity when ploughed under. ft should be borne in miud tliut all tbo mineral constituents. come from tbe soij, and that it ig not possible to Increase these by the growing of gii'een manuring crops, TJie only possible benefit in tiijs rospect is tho more available form that may regult a.s tho green manuring cropg decompose. Tbo only roal additions to tbe sojl wi)l be in tbe form of organic matter and nitrogen. Jt is tberei'ore espential to seleet tboge rrnps tbnt will give tbe largest increase iu tljosu twu (yjistit- , uenta,