عنوان مقاله [English]
Background and objectives: Land use change and long-term sugarcane cultivation can affect soil properties and soil quality. Study of soil properties changes in long-term cultivation soils can help to improvement the agriculture management. The objective of this research was to evaluate chemical properties of the soils under long-term sugarcane cultivation and adjoining virgin soil in order to monitor changes caused by long-term cropping.
Materials and methods: This research was undertaken in fields of the Karun Agro-industry at Diamche area of Shushtar in the Khuzestan province. This study was carried out as a factorial experiment based on a randomized complete design with two factors including fields in seven levels and depth in three levels (0-30, 30-60 and 60-90 cm) and three replications. Soil samples were collected from seven depths in six fields with the long-term sugarcane cultivation and the adjoining uncultivated land. The studied soils were influenced by continuous sugarcane cultivation for over four decades. Then, some chemical properties were measured by standard methods: Soil pH and EC of saturated paste, soluble sodium (Na), soil organic matter content by wet oxidation method, calcium carbonate equivalent (CCE) by titration with hydrochloric, soil gypsum by methods of acetone and soil available K and P was measured. Also, the soil sodium bicarbonate extractable phosphorus (P) by Olsen method and available K using 1 N NH4OAc were measured.
Results: Results indicated that land use change and long-term sugarcane cultivation result in change soil chemical properties. There were not observed signiﬁcant different between soil pH in sugarcane cultivation soils and adjoining virgin soil. Land use change and long-term sugarcane cultivation led to a significant decrease in electrical conductivity, soluble sodium, calcium carbonate equivalent, soil gypsum at different depths of soils. Long-term sugarcane cultivation cause to a significant decrease in the available K (63.2 – 77.9%) at 0-30 cm soil depth. The mean of soil available P and organic matter percentage was higher in soils of sugarcane cultivation lands compared to the adjoining uncultivated land. In general, Results of this study indicated changes of soil chemical properties in surface soil (0-30 cm depth) was higher than other depths (30-60 and 60-90 cm).
Conclusion: results of this research showed the soil chemical properties of different sugarcane fields significantly changed responses to land use change long-term sugarcane cultivation. Exchangeable K was known to be the sensitive indicators following long-term continuous sugarcane cropping. It seems that monitoring the chemical properties of the soil must be considered in order to land management and to maintain the quality of the studied soils.