التغايرات المكانية لبعض صفات التربة الكيميائية و الخصوبية في متعاقبة هيدرولوجية في مناطق زراعة الحبوب في محافظتي النجف و الديوانية

الملخص EN

Kiffil Shinafiya project was selected as it's been conducted and covering the areas of grain crops agriculture in Najaf and Qadissiya provinces.

Lands of this project are considered as a part of the Mesopotamian plain located in between N32⁰ 15′, N31⁰ 30′ and E44⁰ 44', E44⁰ 20′.

Three hydrosequences were disclosed with three transects (T1, T2, T3) in the area of study.

The first hydrosequence was perpendicular on the other two sequences.

Fifteen pedons were outcropped, five pedons in each transect in addition to eighteen more surface samples to be a total samples of 33 locations.

Pedons were morphologically described due to soil survey manual (Soil Survey Staff, 2017).

Spatial distribution of soil salinity showed that the largest area was for the class 4-8 dS.

m-1, while sodium adsorption ratio ranged from 1.05-55.58 where the highest value was in the second pedon of the first transect.

Also, pH of soil showed weak spatial variability due to the range it is included in calcareous soils between 7.02 up to 8.57.

Carbonate minerals showed simple variation as well in the area of study in a range of 114.15-494.37 gm.

kg-1 in the surface horizons and samples where the highest content was in the third pedon of the first transect.

Map of spatial distribution showed that there is a similarity between both of organic matter an organic carbon, where the highest content of the organic matter and carbon was in the thirteenth pedon of the third transect at 21.85 gm.

kg-1 and 12.70 gm.

kg-1 respectively.

Total nitrogen showed highest content of 0.16% in the sixth pedon of the second transect and the thirteenth pedon of the third transect of the hydrose-quences.

Available nitrogen, phosphorus, and potassium content in soil showed that the highest content of available nitrogen was 77.00 mg.

kg-1 in the tenth pedon of the second transect which is located at the end of the hydrosequence, while available phosphorus of the highest value was in the fifth pedon of the first transect that is located at the highest part of the hydrosequence of that transect, and the available potassium did not show a specific distribution spatially.