Ertuğrul Karaş

By Ertuğrul Karaş

Soil erosion is a common problem that complicates watershed management in Turkey and around the world. The main objective of soil conservation work carried out in basins is to ensure sustainable watershed management. The first operation is to define the current situation in the basin. The initial and fundamental objective of erosion estimation based on existing data is generally deciding how to overcome the problem. However, the treatments carried out in most soil conservation studies are similar to each other. Any common, known, or defined methodology about erosion problems in watersheds has not been improved—until now. Considering this problem, the Sustainable Land Use Planning (SLUP) model was developed to determine soil conservation precautions, to set priorities for decision makers and to produce a common solution for rural watershed in Turkey. While the estimated average soil loss was determined to be 7.66 t ha−1 per year, some land use changes were proposed and land use management priorities were set in the direction of the model results to gain sustainable management in the Çelikli basin. At the end of the study, it was showed that the soil loss can be reduced about the rate of 91.2% applying the SLUP model.

Part of the book: River Basin Management

By İrfan Oğuz, Ertuğrul Karaş, Sabit Erşahin and Tekin Susam

The relationship between soil degradation and wheat yield was analyzed in the Çelikli basin, Turkey. Geographic information system (GIS) and factor analysis techniques were used for evaluations. Wheat yield has changed between 600 and 3780 kg ha−1. Soil penetration resistance (PR) was below 2 MPa in 34.92% of the topsoils and was over 2 MPa in the entire of subsoils. The soil loss changed from 0 to 152.8 ton ha−1 year−1. Soils in the study area were generally low in plant-available water (PAW) content. Compared to P, K content was sufficient in top and subsoils in most of the study area. The results showed that B and Zn contents were low, and Cu, Mn, Fe, and Cd contents were adequate. Boron content was less than 0.5 mg kg−1 in 85.5% of the cultivated and 82.9% of the grassland, and Zn was less than 0.5 mg kg−1 in 99.7% of the study area. Low organic matter, low water-holding capacity, high penetration resistance, and deficiency of some macro- and micronutrients were the most important limiting factors of wheat yield. Crop rotation and P, B, and Zn application can help restore soil productivity in cultivated areas of the study area.

Part of the book: Land Degradation and Desertification

By Ertuğrul Karaş

Cotton, which is one of the leading fiber and oilseed crops, consumes 16% of the total pesticides and about 24% of insecticides in the world. In arid climatic regions such as Turkey, most of the plant water consumption is met by surface irrigation methods, while a significant part of it infiltrates deep. During cultivation, a significant portion of pesticides and chemical fertilizers are consumed incorrectly, or unconsciously due to socioeconomic and cultural reasons such as the lack of education of farmers and low economic income. For this reason, it is necessary to understand the correct cultivation techniques from planting to harvest and to manage critical periods in practice. Owing to this, it is necessary to re-evaluate and sustain high-productivity and quality cotton cultivation together with human and environmental requirements. Especially for this purpose, the charts and figures prepared to give direction to experts are a tool for a correct and complete understanding of the topics covered. Considering the objectives and needs of agricultural production, the analysis of the most critical issues required for cotton cultivation from a different perspective will be an important stage for the next steps.

Part of the book: Cotton