VI 



CONTENTS 



Chapter II. The Habitat 



CONCEPT AND ANALYSIS 



27. Definition of the habitat 



28. Factors 



Classification of Factors 



29. The nature of factors 



30. The influence of factors 

 Determination of Factors 



31. The need of exact measurement 



32. The value of meteorological methods 



33. Habitat determination 



34. Determinable and efficient differences 

 Instrumentation 



35. Methods 



36. Method of simple instruments 



37. Method of automatic instruments 



38. Combined methods 



CONSTRUCTION AND USE OF INSTRUMENTS 



39. The selection of instruments 

 Water-content 



40. Value of different instruments . 

 Geotome methods 



41. The geotome .... 



42. Soil borers .... 



43. Taking samples of soil 



44. Weighing .... 



45. Computation .... 

 Time and location of readings 

 Location of readings 

 Depth of samples 

 Check and control instruments 



Physical and Physiological Water 

 50. The availability of soil water 

 Terms ..... 



Chresard determination under control 

 Chresard readings in the field . 

 Chresard values of different soils 



46. 



47- 

 48. 

 49. 



5^- 

 52. 

 53- 



54- 



