Determination of site-specific management zones using soil physico-chemical properties and crop yields in coastal reclaimed farmland

- Crop productivity well responses to ECe, AN, SOC, pH, AK and ρb in coastal farmland.
- Two management zones with different soil attributes and crop yield are identified.
- Management zones had higher suitability over the rotation systems presently used.
- Cultural practices in different rotation systems dominated the management zones.

Delineating site-specific management zones is increasingly attracting attentions due to the need in understanding the intrinsic relationship between spatially varied productivity and soil characteristics, and growing public concern about the productivity of soils and maximum efficiency of crop inputs. Our primary objectives were to characterize the spatial variability of soil attributes associated with crop productivity, to delineate and to evaluate the appropriateness of the resultant site-specific management zones. A total of 15 soil attributes representing soil chemical and physical properties (0-10 cm) and crop above-ground biomass on 85 sampling locations was chosen in a typical coastal newly-reclaimed farmland of north Jiangsu Province, China. Site-specific management zones were identified based upon the spatial variability of soil attributes and crop above-ground biomass, and the appropriateness of management zones was evaluated in comparison with that of the rotation systems presently used. Results indicated that separating the study area into two site-specific management zones was a good compromise between sensitivity and visually variability patterns of soil and crop. The two management zones exhibited significant difference in SOC, SOCD, TN, AN, AK, ECe, pH, ρb, Clay, Ks and crop yield. The obtained management zones had higher appropriateness over the rotation systems presently practiced although the spatial pattern of management zones showed similarity to that of rotation systems. Such results allowed us to conclude that the resultant management zones were mainly dominated by cultural practices used in different rotation systems as the management zones were developed using our preliminary knowledge of cropping rotation systems in this area. Utilizing site-specific management zones would help manage the within-field variability of yield-limiting soil chemical and physical properties.