کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4510552 1321862 2011 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Identifying the spatial variability of soil constraints using multi-year remote sensing
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
Identifying the spatial variability of soil constraints using multi-year remote sensing
چکیده انگلیسی

In north-eastern Australia, soil attributes such as salinity, sodicity, acidity, and phytotoxic concentrations of chloride constrain the growth of crops. It is difficult to delineate constrained areas using conventional sampling methods. Alternatively, where crops fail, over multiple years, to pass a certain yield threshold, we might infer the presence of a soil constraint. For a wheat-growing farm over 10-year period we used remote sensing to obtain a large volume of surrogate yield data, by calibrating an archive of Normalised Difference Vegetation Index (NDVI) to an archive of (limited) ground-based observations. The model used was a generalised additive model that related wheat yield as a non-linear function of NDVI and a linear function of post-anthesis rainfall. Field locations where predicted yield consistently failed to reach the 75th percentile in a given year, over a number of years, we regarded as limited by at least one unknown soil constraint. Soil samples averaged for the constrained locations showed, compared with the unconstrained locations, relatively high concentrations of subsoil chloride, and, in the topsoil, relatively high exchangeable sodium percentage, and unused nitrate nitrogen. On-farm experiments suggested that, for constrained areas, preclusion of monoammonium phosphate (MAP) fertiliser application, coupled to gypsum amelioration, could potentially benefit the farm by A$32/ha/year (MAP) and A$207/ha/3 years (gypsum).


► Wheat yield was modelled statistically as a function of NDVI and post-anthesis rainfall.
► Areas of consistently small predicted yields indicate the presence of a soil constraint.
► Constrained areas had relatively high soil chloride content and exchangeable sodium percentage.
► Changes to phosphorus fertiliser management could benefit the study area by A$32/ha/year.
► Changes to gypsum management could benefit the study area by A$207/ha/3 years.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Field Crops Research - Volume 123, Issue 3, 12 September 2011, Pages 248–258
نویسندگان
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