Development of Tractor Operated Real Time Measuring System for Mapping of Spatial Variation in Soil pH

Abstract

Soil pH is an important physio-chemical property representing soil characteristics and plays an important role in plant growth. Soil pH affects crop yields, plant nutrient availability and soil micro-organism activity. For small areas, measuring the spatial variation in soil pH is feasible. However for the large areas, pH determination of the multiple soil samples by using traditional method in laboratory is very tedious and time consuming. Considering the need and scope of precision agriculture in India, a real time data logging pH measuring system was developed to determine the soil pH directly in the field at specific GPS locations by integrating soil pH sensor and a GPS receiver with a portable data logger. Soil mapping was done for observing the spatial variation in soil pH using ArcGIS. The results showed that the field had variation in soil pH and the developed soil pH measuring system was capable to measure the spatial variation in soil pH. The average soil pH measured by developed soil pH measuring system in different tillage treatments varied from 7.98 to 8.18, 7.60 to 7.94 and 8.01 to 8.21, respectively.

pH zemljišta je važna karakteristika zemljišta koja igra važnu ulogu u utgoju biljaka. Zemljišni pH utiče na prinos useva, dostupnost nutrienata korenu biljaka i aktivnost mikroorganizama u zemljištu. Merenje prostornih promenljivosti pH vrednosti na manjim oblastima je izvodljivo. Ipak, za velike oblasti, određivanje pH većeg broja uzoraka zemljišta na uuobičajeni način u laboratoriji je naporno i dugotrajno. Imajući u vidu potrebe i opseg precizne poljoprivrede u Indiji razvijen je merni sistem za sakupljanje podataka u realnom vremenu, radi određivanja pH zemljišta direktno na parceli na pojedinačnim GPS lokacijama, integracijom pH senzora i GPS prijemnika sa prenosivim data logerom. Mapiranje zemljišta je vršeno radi praćenja prostorne promenljivosti pH zemljišta korišćenjem ArcGIS. Rezultati su pokazali promenljivost pH zemljišta i omogućili da se razvije merni sistem za merenje prostorne promenljivosti. Srednja pH vrednost izmerena ovim sistemom u različitim sistemima obrade zemljišta varirala je od 7.98 do 8.18, 7.60 do 7.94 i 8.01 do 8.21, redom.