ارزيابي كيفي تناسب اراضي خاكهاي گچي براي محصولات مهم زراعي منطقه بردسير استان كرمان

Evaluation of land qualitative suitability of gypsiferous soils for the important agronomic productions of the bardsir area in Kerman province

شهرستان بردسير يكي از مناطق مهم كشت محصولات زراعي استان كرمان است كه در برخي نقاط شديداً تحت تاثير گچ مي باشد. اين تحقيق جهت بررسي خصوصيات خاك هاي گچي و نيز ارزيابي كيفي تناسب اراضي براي محصولات زراعي منطقه انجام گرديد. ابتدا نقشه هاي خاك منطقه مورد مطالعه بررسي شده و سپس 35 مزرعه كه در كل دشت پراكنده و داراي افق تجمع گچ بودند، انتخاب شدند. سپس در هر مزرعه يك پروفيل حفر، تشريح و‌ نمونه برداري از آن انجام گرديد. خصوصيات اراضي نظير شوري، اسيديته، نسبت جذب سديم (SAR)، ظرفيت تبادل كاتيوني (CEC)، گچ، آهك، بافت و ساختمان و اقليم جهت طبقه بندي كيفي تناسب اراضي انتخاب و تيپ هاي بهره وري گندم، ‌جو، يونجه، ‌ذرت، ‌چغندر قند و سيب زميني مطالعه شدند و ضمناً از جداول نيازهاي گياهي و اقليمي گردآوري شده توسط Sys (1991) و با تصحيح و تعديل با شرايط منطقه استفاده گرديد. بررسي نتايج نشان مي دهد كه ميزان حداكثر گچ خاك 31 درصد و متوسط آن 12 درصد مي باشد كه يكي از مهم ترين محدوديت هاي توليد محسوب مي شود. براساس سيستم جامع رده بندي خاك، افق هاي مشخصه Gypsic و Salic تفكيك و در رده Aridisol طبقه بندي گرديدند. بررسي نتايج كيفي تناسب اراضي نشان مي دهد كه دامنه تغييرات كلاس ها براساس روش هاي محدوديت ساده و پارامتريك به ترتيب براي گندم از (S2 تا N2) و (S1 تا N2)، جو (S1 تا N2) و (S1 تا N2)، سيب زميني (S3 تا N2)و(S3 تا N2)، ذرت (S2 تا N2) و (S2 تا N2) چغندر قند (S2 تا N2) و (S2 تا N2)، يونجه (S1 تا N2) و (S2 تا N2) مي باشد كه بهترين شرايط براي كشت جو است. مطالعات انجام شده نشان مي دهد متوسط عملكرد محصولات مختلف در خاك هاي گچي و غير گچي متفاوت مي باشد. بطور كلي مي توان نتيجه گرفت استفاده از خاك هاي گچي نياز به مديريت ويژه دارد.

Evaluation of land qualitative suitability of gypsiferous soils for the important agronomic productions of the bardsir area in Kerman province Abstract Bardsir is one of the important agronomic productions areas in Kerman province, which some positions of it are extremely affected by gypsum. This research was performed to study of properties of gypsiferous soils and evaluation of land qualitative suitability for agronomic productions of the area At first, the land maps were studied, then 35 farms were chosen, they had gypsic horizen and were scattered in the total plane. Then one profile in each farm was excavated and described then catch the samples from all horizons. The total gypsum characteristics, using of agriculture instruments and applying of different inputs were studied. Land characteristics for example: salinity, acidity, Sodium Absorption Ratio (SAR), Cation Exchange Capacity (CEC), gypsum, lime, texture, structure and climate were used to classification of land suitability and land utilization types like of wheat, barely, alfalfa, maize, sugarbeet and potato were studied. The mean while plant and climate tables were gathered by SYS (1991) and givi(1376). The results show that the maximum and average of soil gypsum was 31% and 12%, it is one of the most production limitations. According to 2003 soil taxonomy, the gypsic and salic diagnostic horizon in aridic order was classified. Parent materials, climate, microrelief (topography), physiography, and pendant shapes effect the gypsum formation in the studied erea. Acicular crystals and missilium were separated. Investigation of the land qualitative suitability results show that the change range of classes According to Simple limitation and parametric approaches were ( S2 to N2) and (S1 to N2) for wheat, barely: (S1 to N2) and ( S1 to N2); potato: (S3 to N2) and (S3 to N2); maize: (S2 to N2) and (S2 to N2) ; for sugarbeet (S2 to N2) and (S2 to N2) ; alfalfa: (S1 to N2) and (S2 to N2) respectively which the best and worst position were for barely and potato respectively. The researches show that the medium yield of different production in gypsic and non_gypsic soils is different. Key words: Gypsiferous soils; Bardsir; Qualitative Suitabilty; Classification; Agronomy productions;