Calculation puts the needs can be done with two approaches, ie based on land area and by institutional fields. The approach puts the needs petama is based on the consideration of wet land area, cropping index (IP), and the vast expanse that can be represented from each soil sample taken in the field. For example, rice acreage in Java based on Rice Land Typology Map Balittanah published in 2006 (figure 1) covering 4,090,177 ha with a cropping index of each area of 100 IP-1073649 (+ 25%) and 200 wide IP 3026. 537 ha (+ 75%).
From this data will be needed puts in very much. The second approach through kelembagan, namely by counting the number of BPP in each district and the number of PPL. For example in Cirebon regency there are 400 district or equal to the BPP 400 each have an average of 5 PPL. Then puts to kebuthan Cirebon regency of 2000 pieces.
Of course, this only opportunity in terms of economic promotion, as well as an effective tool in the adoption of research technologies that can be applied directly in the field, especially by farmers.