بررسي خصوصيات ميكرومورفولوژيكي خاك در باغ هاي پسته تحت مديريت زراعي متفاوت در منطقه سيرجان

Soil micromorphological study of pistachio orchards under different crop managements in Sirjan area

Crop management plays a significant role in the crop yield of pistachio orchards. Sand, gypsum and manure separately or together have been applied by farmers in Kerman Province to pistachio orchards. In this study the micromorphological properties of soils in two pistachio orchards were compared with a non cultivated soil in Zeidabad area, Sirjan. Besides, one pistachio orchard in Chah Ghale area was also compared with a non gypsum-treated profile in the same orchard. Five pedons in Chah Ghale and Zeidabad areas of Sirjan were investigated and sampled. Routine physico-chemical and micromorphological analyses were performed. Non- treated soil in Zeidabad area showed a massive microstructure with a few channel pore spaces (channel microstructure). Gypsum interlocked plates increased with depth in this soil. Four hundred and 550 ton/ha gypsum and sand were added to the first orchard in Zeidabad area respectively. Besides, 45 ton/ha manure were also added every two years and the treated soil was mixed to a depth of one meter. A massive microstructure was observed in the surface soil, but vughs and channels increased with depth. Gypsum interlocked plates and lenticular gypsum crystals were found as infilling in this soil. The second orchard has been treated by 330 and 150 ton/ha gypsum and manure, respectively. Besides, 600 ton/ha sand was also added one year before sampling. All treatments were added to the surface and were mixed to a depth of 30 cm. This orchard showed much less pore space as compared with the first orchard. Subhedral crystals were the dominant form of gypsum in the second orchard and crystal (gypsum) pedofeature was found in this soil. The results showed that micromorphological properties of soils were highly affected by different crop management activities. Gypsum treatment in Chah Ghale area caused gypsum infilling compared to non-treated profile. Although gypsum highly changed the micromorphological properties of the treated soil, pistachio yield did not change significantly.