The thesis describes the work done in connections with the following Physico-Chemical investigations of the Punjab soils:-
PART-I AN EXAMINATION OF SOME OF THE FACTORS DETERMINING THE HYDROGEN-ION CONCENTRATION (PH) OF SUSPENSIONS OF PUNJAB SOILS. The variation in pH of soils has formed the subject of a number of investigations and as results suggestions have been put forward for the standardization of these determinations. Certain observations made in a series of soils in 1931 led to this work being undertaken to determine the variations and their causes that might be expected in Punjab soils.
As results of this investigation it is shown that:- a) The glass electrode is best suited for the determination of pH of the Punjab soils b). The soil : water ratio has a very marked effect on the pH of soil suspensions. c). A variation in pH of soil suspensions is brought about on keeping them for any length of time. d). Bacterial activity, Manifested in soil suspensions on keeping, plays an important part in bringing about the variation in pH values.
PART-II. THE CONDUCTOMETRIC METHODS OF ANALYSIS AS APPLIED TO SOIL SURVEY WORK: This part of the investigation deals with the utilization of the principles of conductometry in the chemical analysis of water extracts of soils. A simple apparatus to indicate the change in conductivity during titration is described. A comparison of the analytical results of water extracts of a large number soil samples, analysed both by the ordinary method and the conductometric method for chloride and sulphate contents, shows fair agreement. This method of analysis is shown to be useful in extensive soil survey work involving the analysis of a large number of soil samples. Paper III deals with this part of the work.
PART-III. A STUDY OF THE SOIL PROFILES OF THE PUNJAB PLAINS WITH REFERENCE TO THE TYPE OF NATURAL VEGETATION:- During the soil survey of the uncultivated tracts of land for project purposes in the Punjab it was noticed that areas occurred where a particular type of natural flora was growing abundantly, the other type of vegetation being either absent altogether or present tin comparatively smaller number. In order, therefore, that information might be available which would be of assistance in future soil survey it was decided to examine, in more detail than was necessary for ordinary project work, the soils on which such dominant types soil profiles representing the following dominant types of natural vegetation.
i. Wan (Salvadora oleoides) ii. Okan (Tamarix articulate) iii. Karai (capparis aphylla) iv. Jand (prosopis spicigera) v. Grass of Chimber type(Elehisn oegyptiaca)
As a result of this investigation certain typical characteristics, bearing upon the quality of soils representing the above types of natural vegetation, were revealed and are reported in paper IV.
PART-IV. AS STUDY OF THE SOILS IN THE HILL AREAS OF THE KULU FOREST DIVISION, PUNJAB, WITH REFERENCE TO (I) NATURAL REGENERATION AND NON-REGENERATION OF SPRUCE, (II) ON INVESTIGATION OF SOIL PROFILES UNDER DOEDAR, DPRUCE, BLUE-PINE AND CHIR (PAPER V & VI):- (i) As further use of the systematic examination of soil profiles was made in explaining the absence of natural regeneration of spruce (picea Morinda) in some areas of Kulu forest Division , Punjab. Soil profiles representing areas where there was no regeneration and where the regeneration was very abundant were examined. As a result of this part of the work 9dealt in paper V) it was observed that the depth of A horizon and its organic matter content were factor responsible for regeneration of spruce.
(ii). A number of soil profile under deodar, spruce, blue â€“pine and Chir were examined to investigate the special characteristics of soils bearing the above varieties of forest crops.
Besides brining out the characteristics of soils under the various types of forest crops this work afforded information which was of interest in connection with the genetic classification of the Punjab Hill soils.
As a further result of this investigation important differences were revealed in the podsol type of soils of the Kulu Hill area.
The typical characteristics of the soils bearing the different forest types, the classification differences exhibited by the podsol type of soils of the Kulu Hill areas from podsol type met with in other parts of the world and the causes which led to these differences are all dealt with in paper VI
PART-V. THE DISTRIBUTION OF SESQUIOXDIES, SILICA AND ORGANIC MATTER IN FOREST SOIL PROFILES OF THE KULU HILL AREA:- The distribution of silica, iron and aluminum oxides and organic matter in a number of soils profiles of the Kulu Hill area were examined.
This investigation revealed the characteristic distribution of sesquioxides in the various types of soil profiles. The possibility of the use of this method of soil stud for classifying the Hill soil profiles is pointed out. Paper VII deals with this part of the work.