JWSS - Journal of Water and Soil Science

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The main sources of cadmium in soil-plant continuum in amounts that might present a hazard are liquid and solid wastes of sewage sludge, farm manures and fertilizers. In the southwest of Iran (Khuzestan Province) over 50,000 ha of land is under sugarcane (Saccarum officinarum) cultivation and more than 80,000 ha will be under sugarcane by the end of the year 2000. In these sugarcane fields, about 400 kg ha^-1 diamonium phosphate (DAP) and 400 kg ha^-1 urea are applied annually. There is no data available to show the fertilizers impact on soil, water and plant contaminations in Iran with respect to cadmium. The objective of this research was to compare the extractable cadmium of virgin soils with that of soils under sugarcane.

 Four sugarcane growing stations viz. Haft-tapeh, Karoon, Shoeibieh and Ghazali with cultivation histories of 36, 20, 2 and 1 year, respectively, were selected. In each site, along a transect soil samples from 0-30 cm of both furrows and ridges of cultivated soils and of virgin soils were collected. Electrical conductivity (EC), pH, clay and organic carbon contents, CI and Cd of 101 soil samples were measured according to standard methods. Results showed that increasing either EC or CI increased Cd concentration with its maximum in virgin soils and its minimum in furrows.

 Results also indicated a slight decrease in the Cd content of cultivated soils.

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Field studies of S. cretica Led. damage and potential crop losses on two important cultivars of sugarcane, NCo 310 and CP 57-614, were carried out in southern Khuzestan in 1998-1999.

 CP 57-614 showed greater mean percentage of bored nodes and internodes (20.7%) than NCo 310 (11-2%). Apart from the direct losses in cane weight (cane yield) due to boring from the larvae, cane juice quality is also adversely affected, resulting in lower recovery of sucrose in the factory. Sugar per ton of stalks also was greater in NCo 310 (132 kg) than in CP 57-614 (110 kg). Estimated sugar losses were 0.11 tons ha-1 for every 1% bored and rotten stalks. Other indirect losses are also discussed.

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Experiments were carried out in order to micropropagate sugarcane cultivars through shoot tip and auxilliary bud culture. Rinsing of four cultivars of sugarcane, namely CP-48-103, CP-57-614, CP-69-1062, and NCO-310 in 75% alcohol for 60 seconds and their subsequent disinfection with sodium and calcium hypochloride (1.5% active material) for 15 minutes decreased a significant amount of infection of explants in the medium. The use of the Murashing and Skoog (MS) solid and liquid medium with 1 mg/l Indole Butyric Acid (IBA), 1 mg/l Kinetin, 100 mg/l mio-inositol, 1 mg/l Thiamin HCl, and 2% sucrose had significant superiority (P<0.05) to 1/2 MS solid medium. Also, to increase the multiplication in a sterile medium (In vitro), two kinds of solid and liquid MS medium, with a hormone combination of 1 mg/l IBA, 2 mg/l Kinetin and 1 mg/l 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (BAP) were applied which yielded the highest amount of proliferation. The plants formed roots in Schenk and Hildebrandt (SH) medium with a hormone combination of 5 mg/l IBA and 1 mg/l Kinetin. When activate charcoal was used in the medium, a higher percentage of the plants became rooted and a larger number of adventitious roots were produced than in the dark-light or light treatments.

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Sugarcane (Saccharum officinarum L.)‌ and rotational crops have been cultivated without potassium fertilizers for many years in southwestern Iran. Although potassium was removed from this soil, no response has been reported to K fertilizers by crops. This study was conducted to evaluate the effects of wetting and drying, and cultivation systems on potassium fixation in some Khouzestan soils. The results showed that expandable clay mineral was observed in cultivated soils but not in the non-cultivated soils. This may be related to irrigation, and cultivation practices in this soils. By adding K and sequential wetting and drying the amount of K-available increased in sugarcane, rotational cropping and uncultivated soils from 132.6, 226.2 and, 171.6 mgkg^-1 to 266, 447 and 628, respectively. These results showed that more K can be fixed after cultivating soils, especially by sugarcane, but available K increased by adding K. All surface soils had higher K fixation capacity than subsurface ones. Also, by application K to these soils, the amount of K fixation decreased with increasing wetting and drying times. The K fixation increased by the increase of cation exchangeable capacity. Significant difference was observed between cultivation system and depth of sampling in 1% levels. High K fixation can be attributed to illite minerals depleted from K. Mica-like minerals formed after adding K, and wetting and drying cycles. Amount of K fixation by clay particle samples was more than the same soil samples but in both the same trend was observed for K fixation. Also, drying and wetting decreased K fixation in the last periods. It may be due to trapping K in the interlayer positions.

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The present research was intended to alleviate the problems and costs of deep tilling in sugarcane production in Mian-Ab sugarcane farms located in Khuzestan province, Iran. The main objective was to investigate the feasibility of subsoiling operations with bentleg subsoiler (BLS) equipped with shallow tines, a combination expected to increase the critical depth resulting in less power consumption and improved soil physical conditions. Six treatments arranged in a completely randomized block design were used to measure the draft force (except for the bulldozer mounted rippers), disturbed soil cross-sectional area and penetration resistance. The treatments included (1) subsoiling with rippers mounted on bulldozer, (2) BLS without attachment, (3), and (4) BLS equipped with single tine at working depths of ½ and ⅓ of target depth, (5) and (6) BLS equipped with two tines at ½ and ⅓ target depth. The experiment was replicated three times. The results indicated that BLS without attachment had the highest draft requirement as compared with other BLS treatments with shallow tines. In general, tine attachment resulted in less draft mainly due to displacement of critical depth to lower soil zones. Increasing the number and depth of shallow tines resulted in less draft force. The BLS equipped with two tines working at ½ target depth exhibited minimum drawbar power. The inclusion of shallow tines resulted in 21% reduction in drawbar power requirement as compared to BLS without tine attachment. The cross-sectional area of the soil tilled by ripper was minimum. Furthermore, the tilled area was not uniform and subsequent subsoiling operations were needed. The average soil cross-sectional area per unit width was improved by BLS treatments by a factor of 2.3 as compared with that of ripper. The highest cone index was obtained in plots tilled by ripper the BLS reduced this index in a significant manner. The soil worked with subsoiler equipped with tines exhibited the least resistance. The range of wheel slippage for BLS treatments was 12-16% which lies in the upper end of the recommended range for optimum traction efficiency. The proposed idea proved prominent in subsoiling fine textured compact soils.

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  Sugarcane is one of the most important sugar crops in the world. Because of semi-arid climate and salinity of its cultivation area in our country, increasing salt tolerance of sugarcane is signifying. To achieve this goal determining salt tolerant cultivars and understanding salinity mechanisms in sugarcane are very important. This study was conducted to evaluate 8 commercial and promising sugarcane cultivars at early stage of growth. A complete randomized design with three replicates and four salinity treatments (0, 0.25, 0.5, 0.75 % NaCl) was used in a hydroponics system. The effect of salinity on absorption, transport and accumulation of Na⁺, Cl^- , K⁺ and Ca²⁺ ions in shoot and root was determined. At high level salt concentration, Cl^- content in shoot and root increased. Result showed that sodium accumulation in sugarcane plants was more than potassium. By increasing salinity level, sodium uptake and its translocation to shoots increased reducing growth and dry matter yield of plants. With rising salt concentration from medium (0.5%) to high (0.75%), content of chloride in shoot and root of NCO-310 was constant showed that this cultivar had genetic ability to avoid Cl^- uptake. CP82-1592 with lowest ratio of shoot / root chloride had minimum transport of Cl^- to shoots. Also this cultivar had high content of Ca²⁺ in shoot and low Na⁺/Ca²⁺ ratio at all salinity levels. CP48-103 had low sodium in shoot and relatively low sodium in root. Thus it probably has genetic potential to avoid sodium uptake. At last, exclusion of Na⁺ and Cl^- to older leaves and tillers was seen in CP82-1592 and CP72-2086 cultivars. According to results, to avoid once of absorption and transport, and exclusion of harmful Na⁺ and Cl^- ions were mechanisms that could be used in salinity tolerance of sugarcane.

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Cultivars or species of different plants through physical and biochemical characteristics or indirectly through food diet of host plant can influence behavioral characteristics and efficiency of a natural enemy. This investigation was conducted to determine percentage of parasitism and functional response of parasitoid wasp, Platytelenomus hylas (Hym., Scelionidae) to different egg densities of stem borer, Sesamia nonagrioides (Lef.) and effect of different cultivars on it. At the first stage, eggs of pest were separately collected from fields in three cultivars of CP48-103, CP69-1062 and CP57-614 and then percentage of parasitism in each cultivar was calculated. For determining functional response of the wasp, collected eggs from fields were reared to adult stage at 29±1 ºC, 60% of RH,. Then functional response of wasp was investigated at densities of 2, 4, 6, 8, 14, 20, 30, 40, 50, 60, 70, 80, and 90 of the host eggs for 24h. Analysis of data was done using SAS software. Results showed that egg parasitism by P. hylas in cultivars were significantly different (p<0.05). Type of cultivars influences rate of egg parasitism. Comparison of means by Duncan’s test showed that CP48-103 cultivar significantly differed from two other cultivars: CP69-1062 and CP57-614. Functional response in three cultivars was found to be a type III. Comparison of estimated parameters by Holling model in three cultivars showed that searching efficiency on CP48-103 cultivar was significantly higher than two other cultivars but CP57-614 and CP69-1062 were close to each other. Also, handling time (Th) and the maximum rate of estimated parasitism (T/ Th) on the three cultivars were different and on CP69-1062 they were significantly less than the two other cultivars.

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In this research, samples of sugarcane bagasse were irradiated with various amounts (0, 100, 200 and 300 Kilogray) in an electron accelerator (TT200) to evaluate the effects of electron-beam irradiation on dry matter, neutral-detergent fiber (NDF) and acid-detergent fiber (ADF) degradability parameters. The first samples were dried and then ground for chemical analysis. The ruminal degradation parameters of the samples were measured in fistulated cow 3 (400 kg) at times of 0, 6, 12, 24, 48, 72 and 96 h by the terylene bag method. Data were fitted to non-linear degradation model of Orskov and McDonald to calculate degradation parameters of DM, NDF and ADF. The statistical analysis of degradation of various parameters and effective degradability was accomplished by using the GLM procedure of SAS. After variance analysis, the means were compared with Duncan,s new multiplerange test by using a completely randomized design. The washout fractions of DM as well as NDF and ADF increased linearly (P<0.05) with increasing electron irradiation dose, whereas the potentially degradable fractions of NDF and ADF decreased at first, and then, increased. Also, the degradation rate of the b fraction of dry matter increased. Effective degradability of DM, NDF and ADF increased linearly (P<0.05) with increasing irradiation dose. Electron irradiation at doses of 100, 200 and 300 kGy increased the effective degradability of DM, NDF and ADF at rumen outflow rate of 0.05/h (r) by about 7, 11 and 16% 2, 5 and 7% 3, 7 and 10%, respectively.

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Sugarcane has been cultivated in an extensive area in Khuzestan and irrigated by hydro-flume or siphon and furrow. In a field experiment during 2005-6 at Amir Kabir Agro-Industry, Khuzestan, the effect of every other-furrow irrigation method was studied on sugarcane in regard to irrigation water volume, water use efficiency and quality and quantity of sugarcane. The experiment was conducted in a completely randomized design with three irrigation treatments, including conventional method (blank), variable every other furrow(alternative furrow) and fixed every other furrow. This experiment was conducted by cv. Cp69-1062 sugarcane. The results showed that water use efficiency rates were 0.41, 0.58 and 0.7 kg/m3 for conventional, fixing furrow and alternative, respectively. However, water use efficiency rates were not significantly different in treatments. It had minimum amount of water use efficiency in every other furrow treatments. Maximum water use efficiency, quality and quantity of sugarcane were obtained every other irrigation. Maximum irrigation water was used in conventional treatment and resulted in minimum irrigation, quality sugarcane and water use efficiency. It produced 14.5 ton/ha sugar for 20604 m3/ha application of irrigation. Sugarcane quality and quantity characteristics in variable treatments, except for length number per hectare, were not significant.

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Composting and vermicomposting are two efficient methods to recycle organic wastes. In order to investigate the structural changes in organic matter during the composting and vermicomposting processes, cattle manure and filter-cake of sugar cane were incubated with and without earthworm's presence in a controlled temperature and moisture condition for 16 weeks. Compound samples were taken at 0, 8, and 16 weeks. Carbon, nitrogen and C:N ratio were measured by a CN analyzer apparatus. Solid samples were used for structural analysis using FTIR and solid state CP MAS 13C NMR devices. C:N ratio was decreased with improving decomposition process. The C:N ratio was slightly elevated after 16 weeks of vermicomposting. Structural analysis with both spectroscopic methods showed a decrease of O-alkyl C and increase of aromatic and carboxylic functional groups. The analysis of samples with 13C NMR showed that after 16 weeks, the percentage composition of O-alkyl filter-cake decreased from 41 percent in the first sample to about 33.1 percent. The amount of these compounds in manure samples decreased from 56.7 percent to 43.6 percent. Aromatic compounds in samples of raw filter-cake and manure increased from 12.5 and 13.5 percent to 16.4 and 18.7 percent, respectively. Percentage of carboxyl compounds increased, respectively, from 8.5 and 5.6 percent to 9.7 and 7.2% in the filter-cake and manure sample. Vermicomposts had higher content of aromatic groups compared to composts (In manure samples 18.7 instead of 17.1 percent). After 16 weeks of incubation the aromatic and carboxylic compounds slightly decreased in the vermicomposting process. Analysis of composts and vermicomposts with FTIR and 13C NMR resulted in similar signals with the different frequency intensities. There was a suitable correlation (r=0.897**) among the spectroscopic methods in characterization of composts and vermicomposts

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Considering soil compaction problem in sugarcane fields due to using heavy harvester and haulout equipment under unsuitable moisture conditions, this research aims to assess soil compaction in sugarcane fields located in Da'balKhazaei Plantation unitofSugarcane Development and By-product Company, Ahvaz. Undisturbed soil samples from the furrow (wheel tracks) were collected for measuring soil water content and bulk density. Considering the changes in soil texture of sugarcane fields, for expressing the degree of soilcompactness, in addition to soil bulk density (BD), relative bulk density (BD divided by reference BD) was also determined. The change in soil mechanical resistance with depth was determined by a cone penetrometer. Results showed that most of soil BD values measured in the sugarcane fields were in the range of small root development scale (high limitation). Comparingthe calculated RBD values with optimum value (0.85), it was observed that most of the values were higher than the optimum values recommended for root growth. This shows excessivesoil compaction in the sugarcane fields. The values of cone indices measured in soil profiles indicated that most of the values were higher than either limiting (2 MPa) or critical (3 MPa) values for root growth. Therefore, for improving soil physical fertility and achieving sustainability in crop production, management of farm machinery traffic in sugarcane fields, especially at the harvest time, needs to be reconsidered.

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In this research, a comprehensive simulation model for water cycle and the nitrogen dynamics modeling including all the important processes involved in nitrogen transformations such as fertilizer dissolution, nitrification, denitrification, ammonium volatilization, mineralization, immobilization as well as all the important nitrogen transportation processes including nitrogen uptake by the plant, soil particles adsorption, upward flux, surface runoff losses and drain losses, was used for fertilizer management modeling in a sugarcane farmland in Imam Khomeini Agro-Industrial Company using a system dynamics approach. For evaluating the model the data collected from Imam Agro-Industrial Company equipped with a tile drainage system with shallow ground water and located in Khuzestan province, Iran, were used. The statistical analysis of the observed and simulated data showed that the RMSE for determining the accuracy of simulation of the nitrate and ammonium concentration in drainage water is 1.73 mg/L and 0.48 mg/L, respectively. The results indicated that there is good agreement between the observed and the simulated data. Nine scenarios of fertilization at different levels of urea fertilizer were modeled including one scenario of 400 kg/ha, two spilit scenarios of 350 kg/ha, two spilit scenarios of 325 kg/ha, two spilit scenarios of 300 kg/ha, one scenario of 280 kg/ha and one scenario of 210 kg/ha. Results of the modeling showed that the scenario of 210 kg/ha has the highest nitrogen use efficiency (52.3%) and the lowest nitrogen losses consisted of denitrification, ammonium volatilization and drainage losses (17.82, 7.16 and 92.59 kg/ha, respectively). The results revealed that increasing the consumption of urea fertilizer greater than 210 kg/ha increased the overall nitrogen losses and reduced the nitrogen use efficiency. Meanwhile, this model can be used for managing the fertilizer and controlling the nitrate and ammonium concentrations in the drainage water to prevent the environmental pollution. Also, the system dynamics approach was found as an effective technique for simulating the complex water-soil-plant-drainage system.

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In the present study Hydrus-1D software was used to simulate electrical conductivity, pH and sodium, potassium, calcium, magnesium, chloride and sulfate ions. Field experiments were performed at the Sugarcane Research Center located in south of Ahvaz on sugarcane varieties CP48-103 with four water treatments (one treatment was Karun river water and three treatments were diluted drainage water) and three replications. The samples were collected from 0-30, 30-60 and 60-90 cm soil depth before irrigation and electrical conductivity and anions and cations of soil were measured in the laboratory. Sensitivity analysis and calibration were first performed with the aim of verifying the Hydrus-1D software. The sensitivity analysis indicated that the software had maximum sensitivity to the saturated volumetric water content. Minimum sensitivity was for the inverse of the air-entry suction, tortuosity parameter, residual volumetric water contents and moderate sensitivity was for hydraulic conductivity at natural saturation. Also, the software did not show any sensitivity to empirical parameter related to the pore size distribution that is reflected in the slope of water retention curve. In calibration stage the amount of hydraulic conductivity at natural saturation, residual volumetric water contents, saturation volumetric water contents, the inverse of the air-entry suction, empirical parameter related to the pore size distribution and tortuosity were obtained as 18 (cm/day), 0.04 (cm³/cm³), 0.63(cm³/cm³), 0.012 (cm^-1), 1.2 and 0.6 respectively. The results showed that the coefficient of determination of all parameters was more than 0.85 which confirms the appropriate capabilities of the model in simulation of electrical conductivity, pH, anions and cations. In the modeling carried out the amount of NRMSE was between 11 and 18 percent which indicates good performance of the model. The Nash-Sutcliffe efficiency criterion was obtained 0.72 to 0.8 that indicates a good match of the model with reality. The coefficient of residual mass in this paper was positive for electrical conductivity, pH and sodium, potassium, calcium, magnesium and negative for chloride and sulfate. The positive and negative coefficient of the residual mass shows less and over estimation of the model.
 

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