You have to conduct soil test for micronutrient. take soil sample from field and transfer to soil testing lab. Give following info with soil sample name of farmer name of previous season crop and fertilizer used name of crop which you want to cultivate on that field
i wants to suggest some methods by which you can easily diagonise the deficiency symptoms in soil:
1. as we know that each nutrient have their specific deficiency symptom ie. N show v-shaped yellowing in lower leavess, Fe and Mn show Interveinal yellowing, in case of sulfer veins become chlorotic, boron show twisted leaves etc.
2. in 2nd method it can be easily detected by Soil testing. for this purpose you can take a soil sample from your feild and mark it date of sample, past season crop name and field name. soil sampling labs are available in each distt. and agriculture uni. free of cost.