M. Alizadeh; F. Mirzaei; T. Sohrabi; M. Kavoosi; M.R. Yazdani
Abstract
Water management in cracked paddy soils is an important issue in rice cultivation. In order to investigate the effect of rice straw and zeolite and their interaction effect on the physical condition of soils of paddy fields and prevention of crack, rice straw factor at four levels (0, 0.5, 1 and 1.5 ...
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Water management in cracked paddy soils is an important issue in rice cultivation. In order to investigate the effect of rice straw and zeolite and their interaction effect on the physical condition of soils of paddy fields and prevention of crack, rice straw factor at four levels (0, 0.5, 1 and 1.5 percent) zeolite factor at four levels (0, 8, 16 and 24 tons per hectare) and also moisture stages of soil which are wet and dry stages at 5 levels which have been studied in three replication as factorial based on the complete randomized block design in Rice Research Institute of Iran. Soil distance from the wall of the container, the width of cracks, a few days to reach the crack with a certain width, bulk density and surface cracks were measured. Results showed that adding high levels of residue to delay the occurrence of cracks. However, the addition of zeolite has no significant effect in delaying the cracks. The relationship between bulk density and surface cracks that follow the linear equation, With increasing cracks surface, bulk density is increased. Finally, Can be concluded that the addition of plant residues, causing disappearance of existing cracks and returned to the soil to be the initial state.
M. Karimi Amirkiasar; M. Ardalan; M. Kavoosi; H. Shokri Vahed
Abstract
Abstract
The increasing of yield per unit area is usually achievable by improving the soil fertility level through using (chemical) fertilizers. The purpose of the present research was to evaluate the 6 extraction methods including Olsen, Morgan, Ammonium bicarbonate-DTPA, Colwel, Bray and Mehlich ...
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Abstract
The increasing of yield per unit area is usually achievable by improving the soil fertility level through using (chemical) fertilizers. The purpose of the present research was to evaluate the 6 extraction methods including Olsen, Morgan, Ammonium bicarbonate-DTPA, Colwel, Bray and Mehlich 3 in order to specify a suitable extractant(s) for estimating available phosphorus through using 27 paddy field soils in Guilan province. For farm evaluation, two fertilizer treatments of 0 and 60 kg ha-1 of Triple Super Phosphate in Phosphorus pentaoxide were used. the correlation coefficients between extracted phosphorus by different extractants and relative yields, phosphorus concentration and phosphorus uptake by rice shoots indicated that Colwell, Olsen and Bicarbonate ammonium-DTPA extraction methods had an acceptable correlation with relative grain yield, phosphorus uptake and phosphorous concentration. Thus, with consideration of economic and applicability aspects, extraction speed and its acceptable relationship with plant indices, Olsen extraction method is recommended for available phosphorus.
Keywords: Correlation, Extractants, Phosphorus, Rice
