Toprak Nem İçeriğinin İzlenmesi ve Tayininde Kullanılan Yöntemler

Su kaynaklarının etkili kullanımının önemi, dünya nüfusunun katlanarak büyümesi ve iklim değişikliğinin etkileriyle beraber her geçen gün artmaktadır. Büyük bir su tüketicisi olan tarım sektöründe, doğal kaynaklar için kritik öneme sahip olan suyun verimli kullanılması hedefinin küresel anlamda etkileri ve olumlu sonuçları olacaktır. Tarımda suyun verimli kullanılması hem aşırı sulamalardan kaçınmak hem de bitkilere su stresi yaşatmamak için önemlidir. Bu nedenle kullanılacak su miktarının belirlenmesi amacıyla topraktaki mevcut nem miktarının izlenmesi bir zorunluluk haline gelmiştir. Uygulanacak olan sulama programının oluşturulmasıyla, düzenli sulama uygulamaları yapılacak ve minimum sudan maksimum verim elde edilmesi amacının ilk aşaması tamamlanacaktır. Toprak nem içeriğinin belirlenmesinde uygulanan yöntemler doğrudan ve dolaylı olarak ikiye ayrılmaktadır. Gravimetrik yöntem doğrudan toprak nem içeriğini belirlemek için kullanılırken; dolaylı yöntemler, elektromanyetik yansıma zamanının ve frekansının ölçülmesi, elektriksel direnç yöntemi, nötron saçılımı yöntemi ve toprak su potansiyelinin ölçülmesi olarak açıklanmıştır. Dolaylı ölçüm yöntemleri, doğrudan ölçüm yöntemlerine göre toprak nem içeriğinin izlenmesini uygulamada daha pratik hale getirmek için geliştirilmiştir. Ancak bu geliştirmelerin; ekipman fiyatlarının görece yüksek olması, çalışma aralıklarının sınırlı olması, insan sağlığına tehdit oluşturacak unsurlar barındırması ve ekonomik ömürlerinin sınırlı olması gibi farklı sonuçları olmuştur. Bu çalışmada toprak nem içeriğinin belirlenmesinde kullanılan yöntemler hakkında bilgi verilmiş ve sahip oldukları avantaj ve dezavantajlar incelenmiştir.

Methods of Soil Moisture Content Monitoring and Determination

The importance of efficient use of water resources is increasing with the exponential growth of the world population and the effects of climate change. In the agricultural sector, which is a great water consumer, the goal of efficient using of water, which is critical for natural resources, will have global effects and positive results. Efficient use of water in agriculture is important both to avoid excessive irrigation and to not being in water stress for plants. For this reason, it has become a necessity to monitor the amount of moisture in the soil in order to determine the amount of water to be used. With the constitute of the irrigation scheduling to be implemented, regular irrigation applications will be made and the first phase of the aim of obtaining maximum efficiency from minimum water using will be completed. Determination of soil moisture content methods is divided into two as direct and indirect. While gravimetric method is used to directly determine soil moisture content; indirect methods are described as measurement of electromagnetic reflection time and frequency, electrical resistance method, neutron probe method and measurement of soil water potential. Indirect measurement methods have been developed to make monitoring soil water content more practical in application than direct measurement methods. But these improvements caused different consequences, such as relatively high equipment prices, limited working intervals, threats to human health, and limited economic life. In this study, information was given about the methods used in determining soil moisture content and their advantages and disadvantages were examined.

Keywords:

gravimetric method, TDR, FDR neutron probe, tensiometer,

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