GREEN MANURING EXPERIMENTS.

Taranaki Daily News, 12 March 1919, Page 3

GREEN MANURING EXPERIMENTS.

During the last year a scries of experiments were instituted at the Central School experimental plots in "Poverty Fist," to determino the relative values of various green manuring crops. The following formed the basis 0 f the experiments: Rape, mustard, crimson clover, Soudan grass, lucerne, berseem. Italian lupin, Japanese millet, Hungarian millet, and Soudan grass. As is generally known, green manuring consists in the ploughing or digging under of some rapidly growing crop, i The praotice ha-s three objects:—-(1) The improvement of the texture of the land by increasing the store of humus. This is particularly valuable on both clay and on light sandy soils. (2) The saving of the store -of nitrates, which, on light sandv soil, form with great rapidity, and which may fobeasily be washed away. If some catrih crop is sown (see above list), it will gather up these soluble nitrates, and convert them into other compounds which become more slowly available, on the decay of the plant material(3) For cleaning purposes. When the land is in a very foul condition a good many weeds can he got rid of by growing a smothering crop. " j When leguminous (or pod hearing) crops are grown, the land is also enriched "by the nitrogen gathered from the atmosphere by the bacteria living in the root nodules, and large areas of barren land have been brought under cultivation by ploughing in lupins, etc., ■mrtahly manured, until a soil has open built up. The real difficulty experienced in utilising green manuring and ca-teh crops generally on many soils. i= the war deplete the water supply for the succeeding crap. Indeed, the nrnctiw is to he encouraged only where the rainfall is well over 30 inches. Rut in this respect Taranaki has nothing to fear. While it would not. he wise to advocate wholesale green manuring throughout Taranaki, vet there are several districts in which the judicious use of such crops would he beneficial to the soil. Tnmanv parts the soil is sadly lac-king in humus (decayed vegetable or animal matter!. which helps to bind together loose soil and make it retentive of moisture. A.« pointed out nl.-ove .the store of nitrogen is increased hv the growing of s\mh crops, sccompanied by the accuniMlatij" of humus. The exoeriments carried out nt the Central School Grounds demonstrate the snnpriori-tv under certain conditions of hipin as a green Tinunns crop. A mix-t--r--- of two was u=ed, white lupin (Luninns alhusl and blue lupin 'L.Angnstiifolirisl. the seed hflvnur been obtained from the manafcr of the Tan-vinc-rji horticultural and experimental "tsi.ion. lowing was carried out onrlv in December.,the seeds heinsr planted in rows liinn inches apart. A licht dressin?' nf lime and superphosphate wn = n-n-pn 'm,f ilii. ntVr t T ons under trial r»cniv«d similar treatment Now, nl-tlioiiti-li the soil is of a specially barren nature the bmips nmkc a line disiiliy. overuiTinsr nhnut R'ft (Tin in lieiffht. Tbc roots are hirMv nndnliforous. showing that the nitrogen-gjitherinn bacteria ar« active

Tt hful beep intended to dip- in the hinipo when Ibev i-ftnchpd the ftowprin? ate.™ hp-t on account of thp scarcity of the seed and the promisuHT looV of <■!>? crop it has been decided to retain ! t for seed purposes. This y<?s.r it is the intention o-f the agricultural staff of the Education-Board to ear"' out a ciinitur <»>( of ""d demonstrations in representative «,pi. n „i<. +i,,„„„%,n,,,. t,„„,vi The rp , suits should prove of interest.