Zonal Vegetation of the Tropical-Subtropical Dry Zone

2020 ◽  
pp. 325-403
Author(s):  
Jörg S. Pfadenhauer ◽  
Frank A. Klötzli
Keyword(s):  
Author(s):  
V. P. Belobrov ◽  
S. А. Yudin ◽  
V. А. Kholodov ◽  
N. V. Yaroslavtseva ◽  
N. R. Ermolaev ◽  
...  

The influence of different systems of soil cultivation is considered - traditional (recommended) technology and direct sowing, which is increasingly used under dry conditions of the region. The rehabilitation of the degraded southern chernozems and dark chestnut soils structure during 13 and 7 years of direct sowing, respectively, has not been established. It takes much longer to rehabilitation the aggregate state of soils, which is currently in a critical condition of the content of aggregates> 10 mm in size and the sum of agronomically valuable aggregates. The soils under 60-year treeline, as a control, showed a satisfactory range of aggregates, which indicates a high degree of soil degradation in the past and a long period of their recovery time. The effectiveness of direct sowing usage in the cultivation of a wider range of grain and row crops (winter wheat, sunflower, peas, chickpeas, rapeseed, buckwheat, corn) is due to the peculiarities of agricultural technologies. Abandoning of naked fallows and soil treatments with the simultaneous use of plant residues and cover crops on the soil surface between the harvest and sowing of winter crops provides an anti-erosion effect and, as a consequence, a decrease in physical evaporation, an increase in moisture and biota reserves, an increase in microbiological processes, which are noted in the form trends in improving the agrochemical and agrophysical properties of soils.


Farmers in dry regions of India have a high tendency for leaving their land fallow. To decipher this phenomenon, the study was carried out in the Tumkur district of the central dry zone of Karnataka. Results from the study revealed a positive relationship between the size of land holdings and land fallow. The major reason stated by farmers for leaving their fallow land was the scarcity of rainfall or irrigation, and poor land fertility status. The Tobit regression model was fitted to study the determinants of the decision of farmers to keep the arable land fallow, where, dependent variable considered was the share of fallow land in the total size of landholding of farm households. It was found that the availability of water for irrigation and family labour has a negative relationship with fallow land. Other factors determining the extent of fallow land were the distance of land from residences, poor land fertility status and availability of credit.


Langmuir ◽  
2020 ◽  
Vol 36 (51) ◽  
pp. 15603-15609
Author(s):  
S. Farzad Ahmadi ◽  
Corey A. Spohn ◽  
Saurabh Nath ◽  
Jonathan B. Boreyko
Keyword(s):  

Zootaxa ◽  
2007 ◽  
Vol 1490 (1) ◽  
pp. 1-63 ◽  
Author(s):  
L. J.MENDIS WICKRAMASINGHE ◽  
D. A.I. MUNINDRADASA

Five new species of geckos are described from Sri Lanka by morphological comparison and morphometric analysis leading to review the genus Cnemaspis in the country. The type series of these species were identified from following localities: C. alwisi and C. kumarasinghei from the intermediate zone, C. retigalensis from the dry zone, C. molligodai from the lowland wet zone and C. samanalensis from the mountain region of the wet zone in the country. The high degree of endemicity (90%) shown by Cnemaspis in Sri Lanka could be attributed to geographical isolation. In addition, the taxonomic issue of C. jerdonii scalpensis is discussed and the species C. scalpensis is errected.


2020 ◽  
Vol 9 (1) ◽  
pp. 277-281
Author(s):  
S A Biradar ◽  
Vivek S Devarnavadagi ◽  
Shivalingappa Hotkar ◽  
B C Kolhar ◽  
S C Rathod
Keyword(s):  

2021 ◽  
Author(s):  
M.H.Ashan Madusanka ◽  
◽  
Sandun Sadanayake ◽  
lkMeththika Vithanage ◽  
◽  
...  

In several regions of the dry zone of Sri Lanka, excessive quantities of fluoride (F-) in groundwater have affected the water quality significantly. Apart from the well-known prevalence of dental fluorosis, Chronic Kidney Disease of uncertain etiology (CKDu) is widespread in different pockets in the dry zone of Sri Lanka [1]. Fluoride is one of the substances suspected of being causative of CKDu in the area. Since the kidneys retain more F- than in any other soft tissue and excess F- exposure can cause kidney disease. Within the same zone, the prevalence of CKDu varies by geographic area in a ground water and spatial distribution of selected trace elements in groundwater. The optimum F- level in drinking water, according to WHO guidelines, is 1.5 (mg/L); however, due to the unfavorable climatic conditions that exist in tropical countries, people ingest more water than normal intake, resulting in a high F- intake. The source of F- is geogenic. It has been found that the F- content of basement rocks ranges from 9.5×10-5 to 1.44×10-3 kg/L in the region [3]. Farmers consume about 2-3 liters of water a day to quench their thirst, resulting in a daily F- intake of 3×10-3-1×10-2 kg/L [4].


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