A RECONNAISSANCE SURVEY OF PUMICE SOILS.

New Zealand Journal of Agriculture, Volume XXIX, Issue 6, 20 December 1924, Page 369

A RECONNAISSANCE SURVEY OF PUMICE SOILS.

ROTORUA COUNTY.

( Continued.)

B. C. ASTON,

F.I.C., F.N.Z.Inst., Chemist to the Department

THERE is no land in New Zealand which is so neglected in settlement as that of the pumice type. Any knowledge that can be • gained which will lead to an increased utilization of pumice lands as a whole will, owing to the vast areas which are available, the low price of these, and the ease with which they may be cleared and roaded, contribute largely to the prosperity of the Dominion. But there is pumice and pumice. To the optimist, and one possibly without practical experience of the difficulties in farming .the worst kinds, all pumice lands are latent with wealth and only await railways, roads, and harbours to realize a golden harvest, while to the practical pessimist who has failed on one of the difficult pumice types all kinds are anathema. Each commentator may be in a measure right, but errs in arguing generally from different premises.

It is the aim of this series of articles to classify the different types of pumice soils so that any may be recognized, and that none may suffer unjustly from evil reputation of a neighbour or prosper inequitably from a false comparison. It is not claimed that such initial investigation will resolve all difficulties but classification is the first step to a clear understandings when the facts are known reason may exercise its judgment.

I. MAMAKU— concluded. Before leaving consideration of the area described - under the heading .of Mamaku the writer would draw attention to the illustration showing the relation of the soil, subsoil, and underlying rock (Fig. i). In this quarry at Mamaku the sharp line of demarcation between the hard rhyolitic rock and the soft pumice-gravel subsoil is well shown. The roots of the tree indicated by the remaining stump descended through the subsoil until they rested directly upon the rock, but could not penetrate it. The absence of any parting layer of soil, weathered rock, or organic matter between the rock , and the gravel will be noticed. Above the yellow pumice gravel the subsoil passes imperceptibly .into the mixture of partially decayed pumice and organic matter forming the soil. A further collection of analyses of 1 samples from the Mamaku district is given in the accompanying tables, which confirm the statement as to the uniformity of the mechanical composition of each .. type of soil over a large area. Some additional analyses are given of the “ birch ” soils, and of the cultivated and grassed soils of the Mamaku ' Demonstration Farm. Fig. 2 shows a typical scene on the main Rotorua-Lichfield Road, about four miles distant from the Mamaku Farm, near Steele’s old mill. Between these points the country . is similar, showing great constancy to type. ' . II. ROTORUA BASIN. . The geological history of the lands within the Rotorua crateriform depression is more varied. They may be comprised in the following classes: (i) Lake-terraces overlain . by ejected material, including (a) Rotorua pumice shower, (&) 1886 eruption mud ; (2) recent laketerraces ; (3) river-terraces. . (1.) A great distinction must be made -between the lands on the eastern, or Te Ngae, side of Lake Rotorua (&), which have been covered with calcareous mud deposits since 1886, subsequent to the Rotorua pumice shower, and those lands (a) which have not had the benefit of this top-dressing. This distinction makes a very great difference to the agricultural value of the lands, not . only from the lime present in the mud but also from the finer nature of the material. (2.) Recent lake-terraces are those which have been recently and are still being formed at lake-level by the subsidence of the waters, which is still taking place. In many of these there is evidence, of coarse pumice having been left as beaches round the lake. The soils of these lake-level terraces differ from others in the greater, water content, which is difficult to demonstrate in analyses of . samples. In these ■almost submerged lands the water is so free and abundant that it runs out of the-soil in the process of lifting the latter. It is,, however, evident that the lands are often saturated with water. It is on such coarse soils, which are growing a pasture that would be deemed poor by the ordinary farmer, consisting largely of Yorkshire fog and other weeds, that bush-sick stock recover when pastured .there.

. Gile (“ Cause of Lime-induced Chlorosis and Availability of Iron in the Soil,” Journal of Agricultural Research, October, 1920, vol. 20, p. 34), in experiments with rice, found that; although rice becomes

chlorotic (free from green colouring-matter) in calcareous soils with ordinary percentages of water, it will grow normally in certain calcareous soils if the soil is submerged. Many of the Rotorua lake-side soils for a great part of the year may be so saturated with water that they can be described as nearly, submerged. Chlorosis in plants is a condition which. Gile attributes to a depression in the availability of iron in the soil, and he concludes that rice may be expected to make practically a normal growth if the soils are submerged. This point of view is extremely interesting as affecting bush-sick country. One may reason that as coarse pumice soil at lake-level is free .from bush sickness, although derived from the same class of material as that at Mamaku, the proportion of the water in the soil is the great factor in effecting the change for the better. It is, of course, impossible to submerge the bush-sick lands, but their water-holding capacity may be increased by cultivating, compacting, ' and green-manuring. By such means may . the pumice particles be . made to decompose and yield up their stores of plant-food—particularly iron—which are so obstinately held. As showing how readily under favourable conditions, with the aid of stagnant water and decaying plant-remains, the iron and manganese may be liberated from coarse pumice soils, the photograph, Fig. 4, may be studied. At the Railway quarry near the Rotorua Railway-station, at some quite recent date geologically, marshy conditions must have prevailed, the result being that a large amount of the iron and manganese was leached out of the first few feet of pumice and redeposited where the subsoil became much coarser. The dark nature of the underlying stratum is caused by the coating of the pumice gravel with oxides of iron (brown) and manganese (black) which have been leached out of the top soil. (3.) River-terraces are comparatively rare, and, being of small acreage, are unimportant, but are often lands of high fertility. NATURAL VEGETATION. , Hall and Russell (vol. 4, 'Journal of Agricultural Science) lay stress on the fact that coarseness of soil must be studied in connection with climate (particularly rainfall and temperature). Exact meteorological data for comparison of the Rotorua series of soil with the Mamaku series are, unfortunately, not available. Climatically those stations are different, Mamaku being some 800 ft. above Lake Rotorua and the temperature being lower. The rainfall may be' heavier. These climatic differences may have had their effect in the great difference to be found in the natural plant covering of the two areas. At Mamaku it is all forest, but at Rotorua there is a very puzzling vegetation. With the exception of the Te Ngae lands on the east side of the lake, there is nothing like the Mamaku forest until the hill forests are reached at some 500-600 ft. above the lake. Swampy forest is developing in wet places round the lake, white-pine - pukatea forest at Te Ngae, and pure white-pine at Ngongotaha. When, however, one leaves the swampy shores only manuka or fern is encountered. Dieffenbach (“Travels in New Zealand in 1843, was puzzled by the curious distribution of the woods, and his solution, deduced from the-presence of charred stumps, is perhaps partially true, that the great absence of forest within the Rotorua crateriform depression is due to the activity of

The dark stratum along the foot of the pit has resulted from deposition of the iron and manganese.

the Natives in clearing the country for their cultivation. A patch of rimu-tawa forest may be seen on the Te Ngae flat, but this is the only exception of dry-land forest which the writer has encountered on the lowlands, and the preservation of this may.be due to the missionary influence in early years. . Fletcher (“ Recent Changes in the Vegetation of the Taupo District,” Trans. N.Z. Inst., vol. 47, p. 70, 1914) is of opinion that the succession of the vegetation at . Taupo was in the following order: Fern, tussockscrub, forest. If this succession holds true, in Rotorua the native growth at the lower levels has only reached the scrub stage, two species of manuka (Leptospermum scoparium and L. ericoides) being the predominating'shrubby plants on the lower levels, while the higher levels

are still in the fern stage, Pteridium esculentum (New Zealand bracken) and Coriaria, ruscif'olia (tutu) being the predominating growth. Where thermal activity is present a variety of scrubby growth exists, and where swamp conditions occur special associations of herbaceous swamp plants are also present in fairly large areas, but these are not of agricultural importance.

The only correlation betweeh soil and vegetation detected in the Rotorua district is the occurrence of distinct types of forest in very wet subsoil. At Ngongotaha a pure wood of young white-pine (Podocarpus dacrydioides) is developing almost at the lake's edge on a sandy silt (Fig. 5), and . at Te Ngae, on a sandy loam in similar situation, an old pukatea (Laurelia novae-zelandiae) and white-pine forest has developed.

CONCLUSIONS. The results of analyses of typical Mamaku and Rotorua sandy silts show that they are all soils of excessively coarse texture, but that the Rotorua lake-side sandy soils are superior in water and available iron and phosphoric-acid content. The other Rotorua sandy silts have a higher hydrogen-ion figure (i.e., a less acidity) than the Mamaku series, but the available and total phosphoric acid is still low enough to be regarded as deficient. The sandy loams of Rotorua are pre-eminently fertile and healthy soils. The percentage of lime (CaO) extracted by strong acid solvents is exceptionally high. This constituent probably exerts a beneficial effect in keeping the other plant-foods available. These sandy loams cannot be judged by the same standards as those applied to the sandy silts. The amount of available and total iron present is high. A comparison of the figures given by the Rotorua and Mamaku sandy silts suggests that there is little chemical or physical difference between them. The matter must, however, be studied in connection with the climate, which may differ widely in the two districts, Mamaku being some 800 ft. above these Rotorua terraces. No meteorological records are, however, available for Mamaku. Rotorua (rainfall 40-60 in. annually) may- have the advantage in climate, but this is not certain, as a greater rainfall and lower soil-temperature — conditions which may be safely credited to Mamaku—may be more beneficial to the accretion of humus in sandy silts than lower rainfall and higher temperature. Rotorua certainly has the advantage in the fact that the country has been cleared of forest by the aboriginal owners, and the lands have not had time to revert to a vegetation more woody than that of the fern or scrub stage.; Hence the matter of clearing, cropping, and grassing Rotorua fern and scrub lands is a cheap and simple matter compared with. breaking in the forest country of Mamaku. Whether the same standard for iron should be applied to judge the Rotorua sandy silts as the Mamaku sandy silts is a matter which is better deferred until the other pumice series of the adjacent country are examined. One can at present only say that these analyses emphasize the advice already given to increase the humus content and therefore the watersupply of the soil by green-manuring, and the mineral-food supply by phosphate manuring, which also increases the root-development of the plant and enables a wider area of soil to be penetrated for plant-food. Lime should not be used on sandy silts except for such crops as turnips. All the samples taken in this survey were drawn under the writer’s personal supervision in the field. The soils were taken from cultivated or grassed areas or areas under the native vegetation. They were drawn by means of a sample auger to a uniform depth of pin., the subsoil being taken to a further depth of 9 in. below this, and occasionally a second subsoil was taken 9 in. below the first subsoil. Several cores were taken and mixed together to represent the final sample. When present a full note of the native vegetation was taken. As before, Mr. L. D. Foster and Mr. R. E. Grimmett are responsible for the laboratory work.

U) M O d o CTJ tn m Tfco 01 H V) H Q W cl O - tn bn co - d ts U 'h' O Us Q \ tn *— 1 Q <V ’Ci CD <D tn - nJ 'o d ’ - d 0 _O (D g -2 0 a to <D oo44 co d eg . <d.S2 00 • 10 W) rt £ d ■ art <D a <D o M . ■ $4 4° <D 4-> ■ "d a •CJ <L> 4> ? ■ M A --I O • . .'a S 0 o tn Cl, .2* — V) tn Cu O So’ 'T! d O o ■ > 0 0 u. v bn 0 rt 44 .S d v — bn al C2 R rd 2 d 0 2 £ ft ts*© CO CO o <D aS ■ aJ > *. tn o w O s ■ H S O r d -rj z s §

Laboratory Description, of Soil. (Classification of United States Department of Agriculture, modified.) Analysis of “ Fine Earth ”. passing 2 mm. Sieve. Stones '•and Gravel. Remarks. Fine Gravel. Coarse Sand. Fine Sand. Silt. Fine Silt. Clay. Moisture. Loss on Ignition. aboratoryNo. Mamaku : Rimu-Tawa Soils. No. Description of Soil. (Classification of United States Department of Agriculture, modified.) Analysis of “Fine Earth ” passing 2 mm. Sieve. Stones and Gravel. Remarks. Fine Gravel. Coarse Sand. Fine Sand. Silt. Fine Silt. Clay. Moisture. Loss on Ignition. Mamaku : Rimu-Tawa Soils. S 173 'silt Sandy r-4 28-9 24-7 17-7 7-6 2-8 2-4 13-7 2*1 4 174 2-1 27-8 23’2 16-9 6-3 3'6 3’8 15'3 4-0 Unmanured 200-acre paddock, Demonstration Farm „ . . . . 2’1 27-8 23-2 16-9 6-3 3’6 3’8 15-3 - ■ 4-o Unmanured 200-acre paddock, Demonstration Farm 178 27-8 i6-i Pasture. — Pasture., r-8 23-3 7-8 ' 2-3 7-6 n-9 5-3 No. 12 (spent iron oxide) paddock, Demonstration Farm. ,, • • • • i-8 23’3 7’8 2-3 7-6 n-9 5’3 No. 12 (spent iron oxide) paddock, Demonstration Farm. 180 Pasture. • I-I 27-7 22-1 16-9 7-5 3-x 3-x i6'9 x-7 No. paddock, 181 • . ,, x-3 30-5 27-4 18-7 8*6 2'3 i-6 9-7 4’5 From forest, 182 L-I 30-6 26-0 17-7 8-5 1’2 3-x xx-5 •3-5 From rimu-tawa forest, scenic reserve. } f I.- 1 30-6 26-0 i7-7 8-5 1-2 3’1 n-5 3-5 From rimu-tawa forest, scenic reserve. 183 loam x-5 3i-4 27-5 18-3 9-0 x-9 x-5 8-9 3-8 windmill paddock, 192 1-0 17-7 16-2 ii-9 9-6 7-o 9'5 26-4 Trace Steele’s tramway, near 14-7 r-8 soil. s 59 1’2 12’4 15-5 n-3 34-o 9’5 From No. 9 (pig) paddock, rhyolitic mound, Demonstra- » • • 1-2 12’4 15-5 n-3 34-o 9-5 From No. 9 (pig) paddock, rhyolitic mound, Demonstra825/9A Sandy silt tion Farm. Pasture. c 1*2 27-7 22*1 19’7 8-9 2-9 3-8 12’9 From Martin’s demonstration experiment paddock, 825/9A 986, 989 Mamaku. Pasture. Sandy silt . 1*2 27’7 22*1 19-7 8-9 2-9 3-8 12*9 tion Farm. Pasture. From . Martin’s demonstration experiment paddock. 986, 989 Mamaku. Pasture. R silt) 0-8 28-8 26-7 13-4 5'3 3'2 5'4 15-2 Composite sample of subsoils from railway cutting, spentr Composite sample of subsoils from railway cutting, spent179 J - 1 oxide paddock, and scenic reserve, Mamaku. Mamaku .• “ Birch ” and related Soils. o s 179 336 Sandy loam -.. .. x-4 14’4 17-3 17-5 6-5 3’6 25’3 14-0 4-0 Birch forest, National Timber Company’s cutting. J •• 1 oxide paddock, and scenic reserve, Mamaku. Mamaku : “ Birch ” and related Soils. 338 ,, . . . . 16-3 19-0 9’5 Rimu-tawa, adjoining S 336. s H 336 184 Sandy loam r-4 14-4 17-3 17'5 6-5 3'6 25-3 14-0 4-0 Birch forest, National Timber Company’s cutting. 338 5II/5I3 ,, 16-3 19-0 9'5 Rimu-tawa, adjoining S 336. 5X5/517' } „ .. •• 1’3 2’2 12*9 i6-i 15-0 i6’3 II’I 8-i 3-3x-3 22’6 9-6 xx-4 6-5 Birch forest, Gamman’s cutting. Composite Oturoa top .soils ' 512/514 '516/518 | Sandy silt o-5 16-8 23’4 16-4 6-5 x-4 23'3 10-0 Composite Oturoa subsoils H S 184 335 Sandy silt approaching a sandy loam i-6 • 19'4 21-3 18-0 6-5 2-2 14-8 13-3 4’4 Oturoa Road (near school). 338 Sandy. silt .. ■ .. 8-2 21’7 19’3 l6’2 6’7 r-8 12’9 12'5 9’5 Rimu-tawa, adjoining S 336. 34° ,, 1’6 28-5 21’0 , i8’4 9'5 1’4 io'9 8'7 6’6 Birch ridge, back of Ngongotaha, 850 ft. (Not typical ■ ■ birch country.) 5II/5I3 515/517 1*3 2-2 12’9 i6-i 16-II-I 8-i 2-3 3’1 3i'3 22'6 9-6 n-4 6-5 Birch forest, Gamman’s cutting. Composite Oturoa top soils 512/514 516/518 | Sandy silt o-5 16-8 23’4 16-4 6-5 i-4 23'3 10-0 Composite Oturoa subsoils S 335 Sandy silt approaching a sandy loam i-6 19-4 21-3 18-0 6-5 2’2 14-8 13'3 4’4 Oturoa Road (near school). 338 Sandy silt 8-2 21’7 19'3 l6’2 6’7 i-8 I2‘9 12'5 9’5 Rimu-tawa, adjoining S 336. 340 ,, i’6 28-5 21*0 i8‘4 9’5 1'4 io’9 8'7 6'6 Birch ridge, back of Ngongotaha, 850 ft. (Not typical birch country.)

Rotorua: Soils. R 887 Sandy silt . 7’3 31-0 21*4 14*1 ii-4 3’6 ' 2*0 8-7 7-2 Hinemoa Point, east side. Rough pasture. silt 7-3 3i'O 21-4 14-1 ii-4 3’6 2’0 8-7 7-2 Hinemoa Point, east side. Rough pasture. 879 Coarse . . 8-8 38-1 22-7 8-3 6-3 2*2 i-8 12-6 ’i7-i Ngongotaha, lake-side. Rough pasture. sand 8-8 38-1 22*7 8-3 6*3 2’2 i-8 12-6 i7-i Ngongotaha, lake-side. Rough pasture. ii47 Sandy . 8-5 32-5 16-5 14-1 10-4 2*0 2-9 i5-i 9-i White-pine forest, lake-side. Ngongotaha. silt 8-5 32-5 16-5 14-1 10-4 2’0 2-9 i5-i 9'1 White-pine forest, lake-side. Ngongotaha. H 840 sand 16-8 45’6 17'9 8-3 2-3 1’2 7-6 20-0 Lake-side, Rotorua. Pasture.; sand 16-8 45'6 i7'9 8-3 2’3 1’2 7-6 20-0 Lake-side, Rotorua. Pasture. 482 17-6 41'7 12'8 15-0 3'5 1-2 8-i 24’1 Lake-side, Wairangi East. Pasture. Rotorua : First Terraces above Lake. >> • • • • 17-6 41-7 12-8 15-0 3'5 1-2 8-i 24-1 Lake-side, Wairangi East. Pasture. Rotorua : First Terraces above Lake. H ' 493 Sandy 2’1 21*1 x8-l 15’9 3-i 1’3 25’7 I2-I 4’1 Clayton Road, near Fairy Spring. Manuka. silt 2’1 2I-I 18-1 15-9 3'1 1-3 25’7 I2-I 4’1 Clayton Road, near Fairy Spring. Manuka. 495 I-I 14-2 28-2 15-6 3'5 i-4 24-2 II-2 6-9 soil. Road, R 877 4'3 33'8 21-6 15-6 6-9 i-6 2-1 12-3 ■ Trace Road, 979 Sandy 2’6 . 31'3 23-9 18-5 6-2 0-9 2-5 12-0 Trace ft. 50 1149 1.8-7 2I-I 23-9 II-O 3-8 3’7 .16-3 Trace River-terrace. Pasture. loam i’3 18-7 2I-I 23-9 II-O 3-8 3'7 16-3 Trace River-terrace. Pasture. 1093 Sandy 3’3 29-3 25-1 20’5 5’4 . I-I 2’4 n-5 Trace Arapeeti Reserve, Whakarewarewa Stock Road. Manuka. Rotorua: Upper Lake Terraces. silt 3'3 29'3 25-1 20-5 5’4 I-I 2-4 n-5 Trace Arapeeti Reserve, Whakarewarewa Stock Road. Manuka. Rotorua : Upper Lake Terraces. P 531 Sandy .. , 0*8 23'7 28-7 21*1 8-i i-4 14’7 Trace Malfroy Road. silt o-8 23’7 28-7 2I-I 8-i i-4 14-7 Trace Malfroy Road. R 949 2-5 • 28-9 25-0 18-3 7-i i-o 2-6 12'7 Road. Malfroy 952 2*2 29-1 24'5 18-3 5'2 o-9 5'9 12-3 Cultivated. Road. 955 2-3 27-6 26-7 18-9 6-6 o-8 2-2 13-0 4’5 South .towards 952, 958 2-5 27-6 23-2 i6-8 5'3 o-7 10-9 13-3 Trace ft. 982 3-0 . 33-7 23-9 6-7 5-7 o-7 2-9 xi-8 Ngongotaha terraces, 200 ft. Pasture. «« Ngongotaha terraces, 200 ft. Pasture. 991 1 3’ 36-4 20-3 12-7 4’9 o-6 6-4 14'7 Ngongotaha hillside above top terrace. Fern. «« Ngongotaha hillside above top terrace. Fern. 967 2-3 ■ 29-0 23’7 20’0 6-4 i-i 2-9 12-8 4'5 ft. Above Township 869 2-1 25’4 26-1 18-8 6-2 0-8 4'1 15-4 4-0 association. 871 2-7 27’5 21’7 i8-7 7-2 1-0 5'7 14-1 2-7 to . going 873 2*5 ; 6 22-5 19-3 6-5 x-3 2-6 13-0 3'0 Lowest terrace. paddock. 875 2’9 29*0 22*2 19-5 . 6-5 o-8 2-9 15’4 Trace ft., 961 2-0 29-3 23-4 17-8 5-8 r-6 2-5 16-4 3-o Fern. R 950 (subsoil) 2-8 39’5 21-8 17-7 5'7 1-2 2-0 7-6 Trace R 949. 964 2’6. 23'8 25’1 22'8 9-6 i'7 i'5 in Trace ft. • terrace, Upper to similarity been the soils deposit Rotorua : East Side, influenced by 1886 Eruption Mud. Rotorua : Eas Side, influenced by 1886 Eruption Mud. R 1102 silt Sandy 4-8-28-9 24-6 22-1 5-i i-5 2-0 io-i Trace Wairoa Road, lowest paddocks cultivated. Slight mud layer. silt 4'8 28'9 24-6 22'1 5-i i-5 2-0 io-i Trace Wairoa Road, lowest paddocks cultivated. Slight mud layer. 881 silt sandy 14’2 . 35'7 17-8 12*9 7.7 2-6 i-6 6-9 24’3 Mourea hillside. Tutu and fern. sandv silt 14-2 35’7 17-8 12-9 7-7 2-6 i-6 6-9 24’3 Mourea hillside. Tutu and fern. 1096 Sandy loam 6-i 18-3 26-6 18-7 13'4 5’5 2*2 9'7 5’5 Wairoa Road, 135 ft. Cultivated from tutu and fern. 1099 5’9 21-7 3°-o 22*7 7'9 4-6 I-I 5’4 4'4 Wairoa Road, 320 ft. Cultivated. Sandy loam .. • .. 6-i 18-3 26-6 18-7 13’4 5'5 2*2 9’7 5‘5Wairoa Road, 135 ft. Cultivated from tutu and fern; 5’9 ; 21-7 30-0 22-7 7-9 4’6 . I-I 5’4 4'4 Wairoa Road, 320 ft. Cultivated. 885 4-8 21-8 28-1 21’2 9’4 5-i r-4 7-2 10-9 Clover. Cultivated. H • 519. 1-9 10’1 22-5 38-6 7-i 5-o 15-3 8-6 (pukatea-kahikatea) Te . swampy 521 4’4 22’4 20-5 20-1 6-5 5’8 20'5 Nil Te Ngae R 883 9'4 30-4 23-5 15-9 9’5 4’4 o-9 5’4 19-0 Te Ngae river-terrace. Sandy silt '.. .. 9’4 3»-4 . 23’5 15’9 9-5 4’4 o-9 5’4 19-0 Te Ngae river-terrace. ; H 520 io’6 15’9 12’8 12’4 7’6 2'7 • 3O’o 8'0 s> Subsoil of H/519. Sandy silt io'6 i5’9 12’8 12’4 7'6 2’7 30'0 8-o © Subsoil of H/519.

TABLE 3. MECHANICAL ANALYSES.

Volatile Matter. r-per-cent. Citric-acid Extract, Dyer’s Method : Hall’s Modifica-Hydrochloric-acid Extract 6 £ o tion (“ Available ” Plant-food). (“ Total ” Plant-food). 0 0 . *7* Tl <D d rrt 3 Volatile Matter. i-per-cent. Citric-acid Extract, Dyer’s Method ; Hall’s Modification (“ Available ” Plant-food). Hydrochloric-acid Extract (“ Total ’’ Plant-food). ad.. 00. *T**rJ <D r! 3 Fe (Iron). S O 05 Locality. * On Airdrying. * At ioo° C. On 1 Ignition. 0 2 H.-g £ Lime, CaO. Magnesia, MgO. Potash, k 2 o. Phosphoric Acid, P2O5. Lime, CaO. Magnesia, MgO. Potash, K 2 O. Phosphoric Acid, P2O5. Hydroge Determin pH Vai Extracted by Citric Acid. Extracted by HC1. Mamaku : Rimu-Tawa Soils. ' - •* On Airdrying. * At ioo° C. On Ignition. Tota Nitroge Lime, CaO. Magnesia, MgO. Potash, K 2 0. . Phosphoric Acid, p 2 o 5 . Lime, CaO. Magnesia, MgO. Potash, k 2 o. Phosphoric Acid, P2O5. Hydroge Determin pH Vai Extracted by Citric Acid. . Extracted by HC1. Ma.ma.ku : Rimu-Tawa Soils. > Demonstration or Farm. 0-287 s 173 No. 4 (cultivated) paddock .. 2*42 14-04 0-287 0-145 0-014 0-014 o-oxi 0-22 0-13 0-08 0-02 5-7 o-n8 174 200-acre grassed paddock .. 3-80 15-28 O-3I4 0-028 0-007 0-008 0-003 0-20 o-r6 0-04 0-05 5'6 O-P73 175 200-acre grassed paddock .. 32-00 12-15 0-322 O-I95 0-019 0-020 0-003 0-45 0-15 0-07 0-02 5-6 0-049 176 Eruption dust .. .. 0-82 5-48 0-119 0-036 0-014 0-013 Trace 0-13 o-ii 0-04 Trace 5-8 0-022 177 Rhyolite mound, No. 6 paddock 4'78 10-67 0-232 0-167 0-017 0-009 0-006 0-23 0-13 0-05 0-02 5-7 0-062 178 Spent-oxide paddock, No. 12 7-64 12-91 0-385 0-132 0-019 0-023 0-005 0-22 0-15 0-06 0-03 5-4 0-075 179 Subsoil of No. 178.. 5'82 13-82 0-241 0-061 0-009 0-008 0-004 0*12 0*10 0*04 0*02 5’8 0-066 180 Guano paddock, No. 11 2’96 17-33 0-413 o-i73 0-019 0-024 0-006 0*29 0-15 0'07 0-03 5’9 o-n6 181 Rimu-tawa forest .. 1-64 9-92 0-222 0-120 0-032 0-015 0-004 o-44 0-15 0-07 o-oi 5-6 0-072 182 Rimu-tawa scenic reserve .. 3’12 u-54 0-301 o-iii 0-030 0-013 0:005 0-24 0-12 0-04 o-oi a-6 0-057 183 Windmill paddock, No. 6 1-46 8-99 0-230 O-I35 0-015 0*020 0-005 0*24 0-13 o-o6 0*02 5-5 0-100 192 Steele’s new tram, near bridge 9’52 29-13 0-684 0*192 0*023 0-025 0*010 0'35 0*14 0.08 0-05 5-o 0-071 Mamaku ; “ Birch ” Soils. S 184 Birch forest, Gamman’s cutting 31’21 13'97 0-248 0-038 0*014 o'or6 0’002 0-15 0-14 0-05 O-OI 4’4 0-098 185 Subsoil of 184 7.72 11-64 0-176 0*022 0-005 0'006 0*001 0*14 0’16 o-o8 0*01 5'9 0*112 336 Birch forest, National Timber Com29 25-26 17’34 0*322 0-045 0*011 0*011 0*003 0*17 0-13 0*11 0*01 O*O9O pany’s cutting 338 Mixed forest, National Timber Com30 12-94 14-36 0'357 0’087 0-015 0*017 0-005 0-28 0’17 O’i6 0-05 0-057 pany’s cutting 335 Oturoa Road, near school .. 25 14-82 15’75 0-381 o-i55 0*021 0*024 0*007 0’33 0*20 0*09 0-03 0-069 Rotorua : Lake-level Soils (swampy). D 348/5 Ngongotaha 35-84 10-34 0-158 0-013 O-OII 0-445 0-12 0-102 o-8r /6 ff • • • . 35'20 6-68 0-045 0-009 0-007 0-204 O-IO O-I29 0-85 R 879 if • . . . . . 39 i-8i 12-85 0'393 0-157 0-020 0-033 0-019 0-440 0-130 0-09 0-09 5'5 0-086 887 Hinemoa Point (not swampy) 22 2-02 8-88 o-25r 0-080 0-036 0-027 0-013 0-620 0-280 0-18 0-05 5-8 0-051 1147 Ngongotaha white-pine swamp 31 2-87 15-56 0-386 0-108 0-036 0-023 0-019 I 0-440 0-210 0-14 0-15 5-5 0-163 173 No. 4 (cultivated) paddock .. 2-42 14-04 O-I45 0*014 0*014 o*oii 0*22 0-13 0-08 0*02 5-7 o-n8 174 200-acre grassed paddock .. 3-80 15-28 O-3I4 0-028 0*007 0-008 0*003 0*20 0-16 0*04 0-05 5’6 O-P73 175 200-acre grassed paddock .. 32*00 12-15 0*322 O-I95 ■ 0*019 0*020 0*003 0-45 0-15 0-07 0*02 5-6 0*049 176 Eruption dust .. ■ .. 0-82 . 5-48 0*119 0-036 0-014 0-013 Trace 0-13 0*11 0*04 Trace 5’8 0*022 i77 Rhyolite mound, No. 6 paddock 4’78 10-67 0*232 0-167 0*017 0*009 0-006 0-23 0-13 0-05 0*02 5-7 ■ 0-062 178 Spent-oxide paddock, No. 12 7-64 12*91 0-385 0-132 0*019 0*023 0-005 0*22 0-15 0-06 0-03 5-4 ■ ■ 0-075 179 Subsoil of No. 178.. 5'82 13-82 0*241 0-061 0*009 0-008 0*004 0*12 0’10 0’04 0’02 5-8 0-066 180 Guano paddock, No. 11 2'96 17’33 0-413 O-I73 0*019 0*024 0-006 0*29 0-15 0*07 •0-03 5-9 0-116 181 Rimu-tawa forest .. 1-64 9.92 0*222 0*120 0*032 0-015 0*004 0-44 0-15 0-07 0*01 5-6 0-072 182 Rimu-tawa scenic reserve .. 3’12 u-54 0-301 O*III 0*030 0-013 0:005 0*24 0*12 0*04 0*01 a-6 0-057 . 183 Windmill paddock, No. 6 .. 1-46 8-99 0*230 . 0-135 0-015 0*020 0-005 0*24 0-13 0'06 , -0*02 5-5 0*100 192 Steele’s new tram, near bridge 9’52 29-13 0-684 0*192 0’023 0-025 0’010 0’35 0’14 0.08 0-05 ' 5’0 0-071 Mamaku : “ Birch ” Soils. s s Birch forest, Gamman’s cutting 31-21 13-97 0-248 0-038 0’014 0'016 0’002 0-15 0*14 0-05 0*01 4-4 0-098 184 185 7’72 11-64 0-176 0’022 1 0-005 o’oo6 0’001 0’14 o'i6 0-08 0*01 5'9 0’112 . Subsoil of 184 .. ■ .. Birch forest, National Timber Com29 25-26 W34 0’322 0-045 O’OII O’OII 0’003 0’17 0-13 0*11 0*01 0’090 pany’s cutting Com336 338 30 12-94 14’36 0’357 0-087 0-015 0'017 0-005 0-28 0*17 o-i6 0-05 0-057 forest, cutting pany’s Oturoa Road, near school .. 25 14-82 15’75 0’381 o-i55 0’021 0’024 0-007 0’33 0’20 • 0*09 0-03 0’069 Ngongotaha .. , 35-84 Rotorua.: Lake-level Soils (swampy) 335 D 348/5 0-158 0-013 0*011 0-445 0*12 0*102 o-8x 10-34 35-20 6-68'. 0-045 0*009 0-007 0*204 0*10 0*129 0-85 /6 879 39 i-8r 12-85 0-393 O-I57 0*020 0-033 0*019 0*440 0-130 0*09 0*09 5-5 0-086 887 Hinemoa Point (not swampy) 22 2*02 8-88 0-251 0-080 0-036 0-027 0-013 0-620 0-280 0-18 0-05 5-8 0-051 1147 Ngongotaha white-pine swamp 31 2-87 15-56 0-386 o-io8-0-036 0*023 0*019 0*440 0*210 0*14 0-15 5-5 0-163 R

Rotorua : First Terrace above Lake. R 877 979 1093 Clayton. Road . 1 ft. 50 1 Reserve, ft. 27 23 I I 2-53 1 2-39 Rotorua : First Terrace above Lake. [ 12-50 n-72 1 11-33 I 0-243 0-279. 1 0-227 0-054 O-II2 1 0-043 1 0-027 0-018 1 0-018 0-009 0-013 0-006 ] 0-005 1 0-006 0-23 i 1 0-26 0-13 0-12 0-23 0-03 0-04 0-37 I O-II 0-09 | 6-o I 6-4 1 0-029 0-015 I 0-024 1 I 0-029 ’ . o-oi5 1 0-024 It Rotorua Upper Lake - • P 53i Malfroy Road Settlement, Rotorua .. 3-16 13’22 0-208 0-086 0-022 0-019 0-003 0-24 0-18 0-20 0-20 0-15 0-19 0-09 O-II 0-08 0-02 0-06 0-09 R 53i 949 949952 Malfroy Road Settlement, 50 ft. Malfroy Road Settlement, middle terrace, 450 ft. 34 25 2-60 5'90 13-05 13-04 O’2Q3 0-253 0-062 0-058 0-017 0-027 0-019 0’0i8 O-OII 0-007 6-5 6-5 0-046 0-033 952 955 Malfroy Road Settlement, Rotorua .. Malfroy Road Settlement,- 50 ft. ... Malfroy Road Settlement, middle terrace, 450 ft. 34 25 3-i6 2-6o 5’9° 13-22 13-05 13-04 0-208 0-293 0-253 0-086 0-062 0-058 0-022 0-017 0-027 0-019 0-019 0-018 0-003 O-OII 0-007 0-24 0-18 0-20 0-20 0-15 0-19 0-09 O-II 0-08 0-02 0-06 0-09 6-5 . 6-5 0-046 0-033 955 958 Malfroy Road Settlement, 425 ft. Malfroy Road Settlement, fern slopes, 100 ft. 35 26 2-76 ro-86 12-77 14-60 0-265 0-270 o-ioo 0-070 0-040 0-031 0-015 0-017 0-005 0-009 0-20 0-15 0-12 O-II 0-04 0-05 o-io o-io 6-3 6-5 0-028 0-029 958 982 Malfroy Road Settlement, 425 ft. Malfroy Road Settlement, fern slopes, 100 ft. .35 : 26 2-76 ro-86 12-77 14-60 0-265 0-270 . o-ioo 0-070 0-040 0-031. 0-015 0-017 0-005 0-009 0-20 . 0-15 0-12 O-II 0-04 0-05 O-IO O-IO 6-3 6-5 0-028 0-029 982 99i 99i 967 Mount Ngongotaha, 200 ft. terrace .. Mount Ngongotaha, hillside Mount Ngongotaha, 175-200 ft. above township 23 20 29 2-90 6-44 2-88 13-I3-I7 0-257 0-296 0-293 0-085 O-IOI 0-085 0-026 0-028 0-023 0-022 0-021 0-017 0-006 0-005 0-005 o-34 0-28 0-23 0-23 0-15 0-17 0-09 0-07 0-05 O-II 0-05 0-02 6-6 6-2 0-015 0-015 0-021 967 869 Mount Ngongotaha, 200 ft. terrace .. Mount Ngongotaha, hillside Mount Ngongotaha, 175-200 ft. above . township 23 20 ■ 29 2-90 6-44 2-88 13-13-17 0-257 0-296 0-293 0-085 O-IOI 0-085 0-026 0-028 0-023 0-022 0-021 0-017 0-006 0-005 0-005 0-34 0-28 0-23 0-23 0-15 0-17 0-09 0-07 0-05 O-II 0-05 0-02 6-6 6-2 0-015 0-015 0-021 869 871 Malfroy Road Settlement, highest terrace Malfroy Road Settlement, middle terrace 30 29 4'74 5’66 16-oo 15'00 0-356 0-279 0-144 0-131 0-024 0-037 0-026 0-028 O-OII 0-012 0-48 0’33 0-22 0-36 0-20 0’36 0-19 0-08 0-07 0-05 0-07 Q’03 0-02 6-3 0-064 0-052 0-053 0-052 0-035 0-031 0-034 0-045 871 Malfroy Road Settlement, highest terrace Malfroy Road Settlement, middle terrace 3° 29 4-74 5’66 16-00 15-00 0-356 0-279 0-144 0-131 0-024 0-037 0-026 0-028 O-OII 0-012 0-48 o-33 0-22 0-19' 0-08 0-07 0-05 0-07 0-03 0-02 6-3 0-064 0-052 0-053 0-052 0-035 873 Malfroy Road Settlement, lowest terrace 31 2-60 13-30 0-282 0-081 0-034 o-o 18 0-006 0-14 0-18 0-19 0-04 0-07 0-04 0-13 O-II 0-04 . 6-3 6-2 D 873 875 875 961 9611121/5 Upper Clayton Road, 475 ft. Upper Clayton Road, 475 ft. Whakarewarewa (green-manured) 38 2’86 2-46 19-09 16-10-43 0-300 0-304 0-193 0-129 0-058 0-042 0-023 0-031 O-OIO 0-028 0-006 0-006 0-017 0-36 0-20 0-36 1121/5 1121/3 Malfroy Road Settlement, lowest terrace Upper Clayton Road, 475 ft. Upper Clayton Road, 475 ft. Whakarewarewa (green-manured) 31 38 2-60 2'86 2-46 19-09 13-30 i5’8o 16-85 10-43 0-282 0-300 0-304 0-193 0-081 0-129 0-058 0-034 0-042 0-023 0-018 0-031 O-OIO 0-028 0-006 0-006 0-006 0-017 0-14 0-18 0-19 0-04 0-07 0-04 0-13 O-II 0-04 6-3 6-2 1121/3 1121/4 Whakarewarewa (green-manured) Whakarewarewa .. . 32-80 33-°3 11-69 10-52 0-225 ■O-I79 0-019 0-014 0-024 0-013 0-37 0-21 o-io 0-08 0-06 0-05 0-034 0-045 P 531 : Lime-requirement —on air-dried soil, 0-37 on sol dried a ioo° C 0-38. Rotorua : East Side, influenced by 1886 -Eruption Mud. 1121/4 Whakarewarewa (green-manured) Whakarewarewa .. 33-11-69 10-52 0-225 0-179 0-019 0-014 0-024 0-013 o-37 0-21 o-io 0-08 0-06 0-05 P 531 : Lime-requirement —on air-dried soil, 0-37 on soil dried a ioo° C 0-38. Rotorua : East Side, influenced by 1886 Eruption Mud. R 1102 level 17 1-98 9’93 0-197 0-068 0-027 0-017 0-007 0-48 0-26 0-14 0-08 D H 881 1096 1099 885 36/6 36/7 519 Village Road, Road, Wairoa Road, . Road fern) Road lake-level. 28 10 15 31 2-1-08 1-44 25-65 13 13-10 7-03 10-37 5-17 7-32 5'44 2-36 4-75 0-156 0-247 0-142 o-i53 0-129 0-093 0-262 0-136 0-128 0-146 O-I53 0-119 0-028 0-048 0-045 0-034 O-OIO 0-030 0-035 0-035 0-023 0-024 0-035 0-013 0-012 O-OII 0-009 0-005 0-031 0-043 0-025 0-82 0-67 , 2-10 1-25 1-29 0-42 1-04 1-08 o-6 0-38 0-17 0-47 0-47 0-24 0-02 0-03 0-04 0-05 0-03 0-08 0-06 0-07 5-6-5 0-085 0-055 0-054 0-032 0-184 0-304 0-129 0-031 1-510 I-95O K 883 C 1317/4A Te Ngae, river-terrace Te Ngae, 1886 eruption mud 15 0-90 24-27 5-40 4'67 0-161 O-IOI 0-186 0-034 0-025 0-016 0-006 0-044 1-17 0-64 0-23 0-03 0-09 0-09 0-05 0-05 0-07 6-o RD 36/5 Te Ngae, low-level paddocks 21-25 5'36 0-192 0-017 0-047 O,I 35 0-240 0*178 O-IOI 0-108 1’52 1121/13 Te Ngae, white-pine swamps 23-89 3-51 0-066 £. • 0-020 0-025 2’05 0-76 O-II 1121/14 1121/15 Te Ngae, fern country, low level Te Ngae, subsoil of 14 17-76 21’11 3-09 9-99 0-096 0-188 L • • 0-023 0-037 0-022 O-OII i-74 0-05 o-86 0-32 0-27 0-13 1-598 I-215 1121/16 Te Ngae, raupo swamp 28-56 20-15 0-381 0-043 j 0-063 1-25 0-46 0-21 0-20 0-431 883 I 3 I 7/4 A Te Ngae, river-terrace .. Te Ngae, 1886 eruption mud- ■.. ■ 15 0-90 24-27 5-40 4’67 0-161 O-IOI 0-186 0-034 0-025 0-016 0-006 0-044 1-17 0-64 0-23 0-03 0-09 0-09 0-05 0-05 0-07 0-20 6-o 1-52 1-42 C D 36/5 1121/13 Te low-level paddocks 21-25 23-89 . 5'36 3-5i 0-192 0-017 0-020 0-047 0-025 2-05 0-76 O-II 0*135 0-240 0-178 O-IOI 0-108 0-431 0-066 1121/15 Te Ngae, fern country,, low level ;. Te Ngae, subsoil of 14 Te Ngae, raiipo swamp ... 17-76 2I-II 28-56 3-09 - 9’99 20-15 0-096 0-188 0-381 L • • 0-023 0-037 0-043 0-022 O-OII 0-063 i-74 0-05 1-25 o-86 0-32 0-46 0-27 0-13 0-21 . 1-598 1-215 1121/16

TABLE 4. CHEMICAL ANALYSES. Results, except *,are percentages on soil dried at 100°C.