LASTING EFFECTS OF LIME

Hawke's Bay Herald-Tribune, Issue 187, 25 August 1937, Page 13

LASTING EFFECTS OF LIME

Striking Results in- Lincoln College Experiment CLOVER INCREASES A report of the research work conducted at Canterbury Agricultural Col« lege for the six months ending March 31, 1937, includes an interesting account of an experiment proving the lasting effects of a heavy dressing of lime. During 1923-24 one half of a block of land in field 14 received two tons of lime an acre and the other half no lime. During the succeeding years the whole block has been cropped with various crops of wheat (throe in succession), oats, turnips, rape etc. Most of the crops received lcwt of super, but no lime has been applied to tho block since 1924. In December 1933, a grass mixturo was sown across the limed and uulimed areas and has been top-dressod with 1 cwt of super each autumn. Tho iuixture was: Certified ryegrass 251b, cocksfoot 71b, No. 1 wild-white clover 21b, red clovr (commrcial) 3 lb. During the first autumn, winter and spring there was no noticeable dift'erence botween the pasture on the limed and unlimed areas, the pasture beiug dominautly ryegrass. During the second and third years the clover began to increase in amount in the limer area, while the unlimed are had. remained practically bare of clover and to-day tho dift'erence between the two areas is striking, as is revealed in tho following tables giving the botanical composition, hay yields, and chemical composition of tho two pastures. Tho following is the botanical analysis of three-yoar-old pasture sown on the area which received two toiia ot lime 12 years ago: —

During its first season the pasture showed no difi'erences, but this year (i.e., its third year) the high proportion of clover ou the limed area and the density of weeds, particularly of sorrel, on the unlimed area have been most striking. Hay yiclds were determined and kere again the dili'ereuee be tween lime and nu lime was very noticeable: No lime 19cwt an acre Lime 36ewt an acfu Chemical analysis of sampie3 of material cut for hay was determined on a dry matter basis as follows: — No lime. Lime. Total ash 6.36 7.73 Cao (lime) ...... .34 .605 1J205 (phosphate) .68 .67 Organic matter . . 93.64 92.27 Crude protein ... 7.87 8.69 On this particular area there hns been a marked response in the third year of the pasture on the limed land. A slight lime deficiency does not seem to check good growth of grasses and crops, but if the clover component of a pasture is to be retained, lime in the soil is very necessary. The absence of clovers, the dominance of weeds such as sorrel and the low-yieiding ryegrass on the unlimed plot has been a striking contrast to the association on the limed plot of dense clover and high-yield-ing ryegrass. The .difference in chemical composition of the pastures on the two plota are in keepiiig with the botanical analysis except that with such a high clover content on the limed area, the percentage of crude protein shown iu the above table is lower than expected. The calcium content of only .34 per c«nt iu the samples from the unlimed plot is very low, only the very poorest pastures having such a low lime content. This area is a fair example of Canterbury pasture land and indicates the necessity for heavy applieations of lime in order to maintaiM high-pioduc-ing pastures^

No Lime. Lime. Per cent Per cent Ryegrass 73.4 70.0 Cocksfoot 8.6 10.2 Glovers ".3 14.8 Trefoil 3.8 1.3 Hairgrass #3.8 — Soft broine 2.8 — Sorrel 4.U • — Other weeds .... '1.8 1.2 Other grasses .... — 2.5