Lateritic Red Soil Research Articles

Mineralogical composition of iron oxides in red- and yellow-colored soils from Southern Japan and Yunnan, China

Six soil samples from the Bt2 horizon of red- and yellow-colored soils collected in Southern Japan and Yunnan, China, were used in this study. Detailed mineralogical studies by differential X-ray diffraction analysis showed the presence of hematite in association with goethite in the red-colored soils, whereas no hematite was detected in the yellow-colored soils. Among the samples studied, the increase in the hematite contents was as follows: Terra rossa-like/Red-Yellow soil in Kikai Island, Red soil in Toyota City, Lateritic Red soil in Minami-Daito Island and Lateritic Red soil in Yunnan, China. Since Lateritic Red soil and Lateritic Yellow soil are distributed adjacently on the Pleistocene raised coral reef terrace in Minami-Daito Island, having a fairly similar soil temperature regime, soil pH, soil organic matter and iron oxide contents, the difference in the soil color between the two soils may be caused by the difference in the hydrologic conditions.

EFFECT OF LAND MANAGEMENT, IRRIGATION SCHEDULE AND ORGANIC AMENDMENTS ON PRODUCTIVITY OF IRRIGATED GROUNDNUT

A field experiments was carried out during summer 1996 and 1997 at Vamban to study the productivity of irrigated Groundnut (Arachis hypogaea L.) as influenced by land management using organic amendments under varying irrigation regimes. Adopting land management of ridges and furrows and providing irrigation at 0.8 IW/CPE resulted in higher groundnut pod yield of 1588 kg/ha and benefit cost ratio of Rs. 2.75 under red lateritic soils of Vamban. Application of enriched FYM registered significant increase in plant height, number of pods per plant. pod yield WUE and benefit cost ratio over bio- digested slurry and pressmud in both the years.

FERTILISER APPLICATION TO GROUNDNUT BASED ON SOIL TEST CROP RESPONSE EQUATIONS

Soil test crop response studies were conducted in red lateritic soil of the Regional Research Station, Vridhachalam. Fertility gradients were created and different levels of NPK were applied. VRI I groundnut was raised as test crop. Based on yield of pod and haulm, available nutrient contents in soil at harvest stage and uptake of principal plant nutrient elements crop response equations were developed. Test verification of these equations for their applicability revealed that these fertiliser prescription equations hold good at lower levels of targeted yield upto 20 q/ha beyond which there is deminished response to the applied nutrients.

AGRONOMIC EFFECTIVENESS OF ORGANIC SOURCES AND MUSSOORIE ROCK PHOSPHATE TO PHOSPHORUS ECONOMY IN RAINFED GREEN GRAM

A field experiment was conducted in red lateritic soil during Kharif seasons of 1993 and 1994 to study the cumulative agronomic effectiveness of various organic sources with Mussoorie rock phosphate on phosphorus economy in green gram under rainfed condition. Use of Mussoorie rock phosphate (MRP) alone could not increase the grain yield significnatly. But its efficiency was increased by mixing with organic sources viz., farm yard manure (FYM), enriched bio-digested slurry (BDS) and phosphobacteria inoculation. Application of MRP with seed inoculation of phosphobacteria and enriched BDS alone gave the highest benefit whereas, single super phosphate (SSP) alone was uneconomical under rainfed conditions.

PRODUCTION POTENTIAL AND ECONOMICS OF CEREAL BASED CROPPING SYSTEM IN RED LATERITIC SOILS OF PUDUKKOTTAI DISTRICT

Field experiments were conducted in 1986 and 1987 kharif seasons to assess the production potential and economics of maize and varagu based intercropping system under rainfed conditions in red lateritic soils of Pudukkottai district of Tamil Nadu. Amog different intercrops tested, black gram is the best intercrop for maize based intercropping system and varugu based intercropping system. Further analysis showed that yield equivalent, land use efficiency and net profit were significantly increased by grain legumes intercrop and more than compensated the losses in main crops (maize and varagu), Maize and varagu normal sowing+ one row of black gram (1:1) proved to be the best combination by recording maximum grain yield equivalent, LER and net profit.

EFFECT OF FYM, NITROGEN AND POTASH ON YIELD AND UPTAKE OF NUTRIENTS IN GROUNDNUT

A study was taken up in the red lateritic soil of Vridhachalam to find out the effect of N, K, and FYM on the yield and uptake of nutrients in groundnut. The trial was conducted in three seasons in a randomised block design with 32 treatment combinations which consisted of 2 levels of FYM (0 and 6.25 tons/ha) four levels of N (0, 9, 18 and 27 kg N/ha), and four levels of K (0, 27, 54 and 81 kg K2 0/ha). The results showed that application of 9 kg N, 54 kg K2 0 and 6.25 tons FYM/ha significantly increased groundnut pod yield over the other levels tried. Oil content in kernel was enchnced by K application at 54 kg and 81 kg K2 0/ha. N and P uptake were increased by application of FYM at 6.25 t/ha and K at 54 kg K2 0/ha respectively.

FERTILISER APPLICATION TO GROUNDNUT BASED ON SOIL TEST CROP RESPONSE EQUATIONS

Soil test crop response studies were conducted in red lateritic soil of the Regional Research Station, Vridhachalam. Fertility gradients were created and different levels of NPK were applied. VRII groundnut was raised as test crop. Based on yield of pod and haulm, available nutrient contents in soil at harvest stage and uptake of principal plant nutrient elements crop response equations were developed. Test verification of these equations for their applicability revealed that these fertiliser prescription equations hold good at lower levels of targeted yield upto 20 g/ha beyond which there is deminished response to the applied nutrients.

EFFECTS OF AMENDMENTS ON SOIL CHARACTERISTICS AND PLANT RESPONSES IN GROUNDNUT - BLACK GRAM CROPPING SEQUENCE

Studies were made under red lateritic soils of Vamban for finding out the effects of soil amendments, both organic and inorganic like pressmud, rice husk, FYM, lime and gypsum on the soil physical properties and yield of groundnut. The results revealed that the yield of groundnut was signi ficantly increased by application of lime (4 t/ha). Soil hardness was not significantly affected, How ever, the pH of soil was significantly increased due to application of lime (4 t/ha) and pressmud (5 tha). There was indications of the residual effects of amendments on the subsequent crop, blackgram.

INFLUENCE OF ORGANIC AND INORGANIC AMENDMENTS ON CRUST PRONE SOILS

Field experiments were conducted in red lateritic soils of National Pulses Research Centre, Vamban, for investigating the influence of organic and inorganic amendments for overcoming soil crusting and hardening conditions using black gram (KB 51) as test crop. Results showed that bulk density and soil hardness were favourably influenced by application of pressmud (5 tha). Grain yield of black gram increased due to application of amendments from 31.8 to 74.5% per cent. Experiment on the residual effect of amendments indicated positive influence on the yield of the succeeding crop.

Governments and Culture: How Women Made Kerala Literate

A SINGLE IMAGE dramatized Kerala's literacy for me. I was on a bus lurching northwards out of Ernakulam early on a monsoon morning in July 1968. Heavy rain bubbled into the red laterite soil and surged down the sides of the road like strong tea. The canvas window-curtains were let down to keep out the rain, and the inside of the bus steamed. At the first stop, I lifted the curtain to let in some air. A few metres away, an old woman dressed in white sat dry and comfortable on the narrow verandah of her house. What startled me was what she was doing. She peered intently through thick spectacles, and propped expertly against her crossed leg was-her morning newspaper. I had been teaching in a high school in Punjab in north India for about a year at that time, and among 150 boys who were my pupils, only one wore spectacles. Newspaper-reading, even among men, was not something I commonly saw, and I could not remember having seen an old woman reading a newspaper. This was the beginning of my perplexity about what made Kerala literate. Though I could not have known it then, female literacy in Kerala in 1971 proved to be 54 percent; in Punjab, only 26 percent (Table 5). This essay tries to explain why Kerala is India's most literate region. According to the census of 1981, 69 percent of all Kerala's people were literate, though the all-India rate was a mere 36 percent. Maharashtra, the most literate state after Kerala, had a rate of only 47 percent.' (For the problem of defining literacy, see the Note at the end of this essay.) I have long agonized over any short explanation of what made Kerala literate. Was it the persistent policies of far-sighted governments or something peculiar to Kerala's culture? My best proposition would be: governments and their policies affected the timing at which particular groups of people in Kerala became literate; but culture2-and the most important

Vesicular-arbuscular mycorrhizal fungal sporocarps associated withPennisetum pedicillatum

Sporocarps of vesicular-arbuscular mycorrhizal fungi occurring in the rhizosphere and roots ofPennisetum pedicillatum, growing in a red laterite soil were studied. The characteristic features of the sporocarps of each endophyte are described.

Ecology of collembola in a deciduous forest floor of Birbiium District, West Bengal in relation to soil moisture

Abstract Numerous workers like Bellinger (1954), Sheals (1957), Christiansen (1964). Rapoport and Najt (1965), Choudhuri and Roy (1966, '67 and '72), Choudhuri and Bhattacharyay (1975), and Mitra et 01 (1977), have studied the qualitative and quantitative ecology of Coliembolan population in different parts of India and abroad. But the Collembolan population of a deciduous forest of Dirbhum district has not been attempted so far. In view of this, the present communication deating with the effect of soil moisture on the Collembolan population and their distribution in red laterite soil of Dirbhum district, West Bengal has been discussed.

Fungal populations in the rhizosphere of peanut (Arachis hypogaea L.)

A comparison of fungal populations in the rhizospheres of eight varieties of peanut grown in a red lateritic soil amended with farmyard manure was made by the dilution-plate technique. There was a marked increase in fungi in the rhizospheres of TMV 2, TMV 4, Pollachi Red and EC 1698, the increase was smaller in Spanish Improved and RS 1 while very little rhizosphere effect was shown by TMV 3 and Pondicherry 8. Age of the plant had a significant influence on numbers of fungi in the rhizosphere. High R/S ratios were obtained when the plants were 30 days old, at which time attained maximum vegetative growth and started to flower. The ratios gradually decreased after that age until the plants were three months old when there was again a small increase. This later rise in fungal populations is interpreted to be due to an increase in microbial activity around dead or senescent roots. No correlation could be established between numbers of root nodules produced by a variety and its rhizosphere effect. Preferential stimulation of certain fungi in the rhizosphere of some of the varieties was noticed.

Rate of clay formation and mineral alteration in a 4000-year-old volcanic ash soil on Saint Vincent, B.W.I

The surface of a large fan of pyroclastic deposits erupted about 4,000 years ago has weathered to a clayey soil generally 6 ft. thick. The weathered deposits were originally andesitic ash consisting largely of glass and the minerals anorthite, labradorite, hypersthene, augite, and olivine. Fine vitric ash has altered to halloysite.4H ~2~ O, allophane, and hydrated ferric oxide. The vitric lapilli have decomposed to halloysite.4H ~2~ O. Anorthite crystals are etched in the soil and frosted in the underlying ash. Many hypersthene and fewer augite and olivine crystals in the soil are etched. Labradorite, hornblende, and magnetite are unaltered. The 4,000-year-old soil represents an early stage in the formation of the Yellow Earth soils of St. Vincent, which may themselves be classified with the yellow-brown volcanic-ash soils of Japan. Halloysite.4H ~2~ O has been redeposited in some late Pleistocene ash beds on St. Vincent to form dark brown, waxlike braunlehm. Whether or not the yellow-brown volcanic ash soils of St. Vincent represent an early state in the formation of a lateritic red soil cannot be demonstrated. Clayey soil formed from ash at an average rate of 1 1/2 - 2 ft./1,000 years on St. Vincent, and glass decomposed at a rate of about 15 gm./cm. ^2^ /1,000 years. The slight degree to which the unstable minerals anorthite, olivine, and the pyroxenes are altered contrasts sharply with the decomposition of the glass. Survey of the literature suggests that mineral grains have altered more rapidly in some podsols of the temperate regions than in the volcanic ash soils of St. Vincent. This contrast in weathering rate may perhaps be explained by the low pH of podsols and chemical effect of the rapidly decomposing glass of the ash soils.

Studies on Aqueous Suspensions of Insecticides. Part V. The Sorption of Insecticides by Soils

It is suggested that if the vapour of an insecticide is rapidly adsorbed by a substrate the rate of volatilisation of the molecules of insecticide particles lying on the substrate is greatly increased. This explains the rapid loss of effectiveness of wettable powders on some soils. After the insecticide has been sorbed it is concentrated at and near the treated surface but afterwards slowly diffuses inwards. This diffusion reduces recoveries of insecticides from surface scrapings.DDT can be recovered quantitatively from Uganda mud blocks 12 months after sorption is complete. Therefore, on this mud at least, catalytic decomposition does not occur.A test has been devised for measuring the sorptive capacities of soil samples for non-polar vapours. It indicates if a soil is highly active but those with lower or negligible activities do not give a good correlation.A survey of 18 soils from different parts of the world suggests that rapid inactivation of an insecticide by sorption should be expected on any red lateritic soil. Generally, others are inert or show only low activity.Attempts to reduce or abolish the sorptive powers of Uganda soil have not been successful and the only effective method known at present is to limewash the walls before spraying. Pretreatment with a size solution also stops sorption but, unlike limewashing, at the same time reduces the efficiency of a subsequently applied wettable powder.Finally, work by various authors on the inactivation of insecticides on mud surfaces is reviewed.

The assessment of structure in tropical soils

A comparison of methods of measuring the structural condition of cultivated surface soil was made for two important East African soil types.The soil samples were drawn from two field experiments: (i) a tillage trial in coffee on a porous red lateritic clay soil of recent volcanic origin; (ii) a rotation trial for cotton, on a red sandy lateritic loam of granitic origin.Of the measurements on soil cores, total porespace and field capacity (⅓ atmosphere) showed little change, while percolation rates, free-draining pore-space and a new rainfall acceptance test all reflected the observed field behaviour of the soils, and showed fairly close and highly significant correlation. Field sieving of dry clods gave highly significant differences in the lateritic clay, the stronger clods indicating the poorer soil condition. Drysieving for ½ mm. crumb was ineffective, as was wet-sieving after wetting under vacuum. Wetting by immersion gave some differences between treatments, but higher variability and no significant correlation with free-draining pore-space. Wetting by rainfall impact on dry crumbs gave the best wet-sieving tests on the clay soil. Different sieving techniques gave inconsistent results on the sandy soil. Crumb structure measurements are not efficient indications of structural conditions on these soil types, which are of wide occurrence in tropical countries.

Reversion of ferric iron to ferrous iron under water-logged conditions and its relation to available phosphorus

It is known that acidic red lateritic soils are usually deficient in available phosphorus, and whenever any soluble phosphates are added to such soils they become fixed and non-available to plants. It is believed that added phosphates make insoluble compounds of ferric phosphates with iron salts in the ferric state. Since ferrous salts are more soluble than the ferric salts, it suggests itself that if in the soil we can keep the iron in the ferrous state or can effect the conversion of ferric salts into ferrous salts it may be possible to reduce the formation of insoluble iron salts with phosphorus and thus increase the amount of available phosphorus by reducing phosphate fixation. With this object in view red latoritic soils from Dacca Farm area were kept under water-logged condition and the effect upon the conversion of Fe3+ into Fe2+ state and the change of readily soluble phosphorus were studied from time to time.

HIGH MAGNETIC EFFECT OF LATERITIC SOIL IN CUBA

During the course of a conventional vertical magnetic survey in Cuba, it was found that many stations underlain by lateritic red soil gave unusually erratic values. A susceptibility determination of the soil showed it to have a value of [Formula: see text] cgs.

Bioassay of available trace metals from Australian soils

A study was made of various factors influencing the microbiological assay of available iron, zinc, copper, manganese, and molybdenum. Aspergillus niger (M.) was chosen as the best test organism from a group of 9 fungi, 1 alga, 1 yeast, and 6 bacteria. The composition of the basal medium could be altered markedly without affecting the availability figures. A new method of purifying the medium with A1203, gave good deficiency symptoms for Fe, Zn, Cu, and Mn, but Nicholas's method was superior for removing Mo. It was found necessary to sterilize the soil, preferably by autoclaving. The availability of 15 micronutrients was determined by bioassay from 278 surface and 164 subsoil samples from eastern Australia. Seven soil groups, viz. 3 pedalfers, "red loam", acid humic, and podzol, and 4 pedocals, rendzina and terra rossa, chernozem, red-brown earth, and desert soil, showed more deficiencies than all other soil groups bioassayed. Even within these seven groups non-deficient soils also occurred. The commonest deficiency detected was that of Zn, followed by Cu, then by Mo, hut deficiencies of Fe and Mn were rarely found. Usually surface soils with a well-developed root zone were less deficient than subsoils. Fewer deficient samples were obtained from meadow soil, alkaline humic, volcanic tuff, and brown earth than from all other soil groups. There was a fair correlation between the availability of Zn, Cu, and Mo to A. niger (M.) and availability to plants, but none for Fe and Mn. The fungus was able to obtain adequate amounts of micronutrients from a variety of insoluble salts or oxides of Fe, Zn, Cu, Mn, and Mo, some of which were known to be unavailable to plants. A number of soils, e.g. red loam, laterite, and desert soil, inhibited the growth of the mould in complete medium. This effect was due to active fixation of added micronutrients, especially in soils rich in calcium carbonate and in red loams. No evidence was obtained that microbial fixation of trace elements occurred in deficient soils; but most major and minor elements were fixed by microorganisms in very deficient, acid-washed, quartz crystals, with the exception of Ca, which was not significantly affected, and of Fe and Zn, which were released by microbial activity from the minute amounts of contaminants present.

Water Problems of Kitui District, Kenya

KITUI DISTRICT KITUI DISTRICT in Kenya Colony \EAST AFRICA , has many problems, but of paramount '-i -' -/7-' importance, and related to most of the Xk v' (~ others, are those concerned with water. /UGANDA/ o_ K E N Y A I _ Water is the principal determinant of :'ir-: irobi.,:^uI land use. Its yearly presence or absence {~~( 'i W9 w ^means prosperity or possible starvation. Mo.ba>a< Kitui District occupies an area of TAN G A N Y IKA iNDIAN I8,ooo square miles, of which 6000 is ~\^\t~ (^WZANZIBAR :N i: Native Reserve. It lies, for the most part, -~~8^OCEAN -s-^ I -. -8~at elevations of 2000 to 4000 feet 0/ 100000: between the coastal plain and the high,oo 200 .... 20 idoGl :7,O' M JO :KM: lands to the west. Hills of gneiss and 02:8 , 36 GEOGR'REV1EW,0oct.,10o schist rise above a dry, rolling, eastwardFIG. i-Location map. sloping plain of red lateritic soils covered with thornbush except where scattered native shambas dot the countryside. There are no permanent streams; in wet periods the district is drained by sand rivers (Fig. 7), the largest of which, the Tiva and the Thua, may barely reach the Tana River but usually end in the bush. A population of 214,000, including fewer than Iooo non-Africans, is concentrated in the southwest around Kitui Township, where the land is higher, hillier, and wetter. The inhabitants, the Akamba, are of eastern Bantu stock and in the past were one of the more backward tribes of Kenya-and the indigenous tribes of that colony were among the least advanced in Africa. The Akamba are agriculturists, but they also keep large herds of cattle and goats; on the Yatta Plateau, however, and around the confluence of the Kithioluo and Tana