Seyed Majid Mirlatifi - Profile on Academia.edu (original) (raw)

Papers by Seyed Majid Mirlatifi

Precise estimate of evapotranspiration (ET) or crop water requirements crucial for improving wate... more Precise estimate of evapotranspiration (ET) or crop water requirements crucial for improving water resources management and eventually increasing water use efficiency. Considering the vast varieties of crops cultivated on large scales, calculating precisely the crop water requirement from ordinary methods of estimating reference evapotranspiration is difficult and in some cases even impossible. Therefore, it is necessary to develop methods to compute crop water requirement in large areas with sufficient accuracy. One of such methods is to use remote sensing data which covers a much larger areas as compared with methods depending on field weather data. One of the most well known methods to compute actual ET from remote sensing data is SEBAL method (Surface Energy Balance Algorithm on Land). In SEBAL method, all fluxes of the energy balance at the earth's surface including net radiation, soil heat flux, and sensible heat flux are calculated from satellite images and finally actual ET is computed based on the energy balance at the earth's surface. It is intended to evaluate spatio-temporal variation of daily ET in Mirza Kochakkhan sugarcane Agro-Industry farms located in southern part of the Khosetan province using MODIS images for 10-day periods during a growing season in 2006-2007. The results obtained indicated that the SEBAL method was an efficient method to estimate actual ET during the growing season. Maps of actual ET generated by ERDAS and GIS software showed that fields which were well irrigated or had a good crop cover had the highest values of ET. However, actual ET decreased for areas with less crop cover or dry fields. The data obtained from the generated maps of actual ET were closer to the data obtained from the field with a coefficient of determination of R 2 =0.77.

Evaluating Silage Maize Production Under Pulsed Drip Irrigation

SSRN Electronic Journal

Producing daily actual evapotranspiration (ETa) maps with high spatial resolution has always been... more Producing daily actual evapotranspiration (ETa) maps with high spatial resolution has always been a challenge for remote sensing research. This study assessed the feasibility of producing daily ETa maps with a high spatial resolution (30 m) for the sugarcane farmlands of Amir Kabir Sugarcane Agro-industry (Khuzestan, Iran) using three different scenarios. In the first scenario, the reflectance bands of Landsat 8 were predicted from the moderate resolution imaging spectroradiometer (MODIS) imagery using the spatial and temporal adaptive reflectance fusion model (STARFM) algorithm. Also, the thermal bands of Landsat 8 were predicted by the spatiotemporal adaptive data fusion algorithm for temperature mapping (SADFAT). Then, ETa amounts were calculated employing such bands and the surface energy balance algorithm for land (SEBAL). In the second scenario, the input data needed by SEBAL were downscaled using the MODIS images and different methods. Then, using the downscaled data and SEBA...

Journal of Plant Nutrition

Knowing the concentrations of the nutrient elements in soils is important due to their toxic effe... more Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split Split Plot design based on the Randomized complete Block (RCB) with two treatments (well's and wastewater), and eight subtreatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy-loam soil, in Shahrekord, Iran. Soil samples were collected from 0-30 and 30-60 cm depth for measuring nitrate (NO 3-), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform (FC) were also measured at the soil Keywords Soil chemical properties, Subsurface drip irrigation, Wastewater and dripper installation depth.

Agricultural Water Management an International Journal, Jun 1, 2009

parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In h... more parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In humid regions, heavy rainfall can cause NO 3 pollution whereas in arid and semi-arid regions (Jalali, 2005) excess irrigation can be the cause. Management and control of NO 3 leaching are difficult because NO 3 losses are often intermittent, and linked with seasonal land management, irrigation practices and fertilizer applications and/or irregular events, such as rain (Carpenter et al., 1998; Barton and Colmer, 2006). A high NO 3 concentration in the root zone is one of the major concerns in extensively irrigated areas, where excess water needs to be applied to control salinity that results in deep percolation, one of the sources of water to recharged groundwater aquifers beneath irrigated lands (Klocke et al., 1993; Watts, 1997). Applying N at a rate less than optimal (Schroder et al., 1998) and/or using a variable deficit irrigation scheduling regime (Sexton et al., 1996) can reduce NO 3 leaching. NO 3 leaching has been studied under different irrigation and fertilizer management regimes for semi-arid and arid climates

Diurnal variations of photosynthetic gas exchanges in two Iranian pistachio (Pistacia vera L.) genotypes

Diurnal variations of net photosynthesis (A), stomatal conductance (gs) and transpiration (E) rat... more Diurnal variations of net photosynthesis (A), stomatal conductance (gs) and transpiration (E) rates were assessed at the leaf surfaces of two pistachio (Pistacia vera L.) genotypes, in reference to diurnal fluctuations of leaf temperature (Tleaf), vapor pressure deficit (VPD) and photosynthetic photon flux density (PPFD). In this experiment, diurnal changes of net CO2 assimilation showed a two-peak pattern in which the first peaks were appeared at 9:00 and 8:00 in ‘Badami’ and ‘Qazvini’ genotypes, respectively. Also, the second peaks emerged at 16:00, and the lowest assimilation rates were observed at 15:00 in both genotypes. The corresponded PPFD with the highest net assimilation rate were achieved at 1500 and 1150 µmol m-2 s-1 in ‘Badami’ and ‘Qazvini’, respectively. Diurnal pattern of net photosynthesis rates was correlated with stomatal conductance ¬(r=0.76) and transpiration (r=0.73) rates. It seems that stomatal conductance in 'Badami' was primarily limited by VPD and ...

Comparison of steady- and unsteady-state drainage equations for determination of subsurface drain spacing in paddy fields: a case study in Northern Iran

Paddy and Water Environment, 2013

ABSTRACT In Northern Iran paddy fields, waterlogging is a serious problem. Provision of subsurfac... more ABSTRACT In Northern Iran paddy fields, waterlogging is a serious problem. Provision of subsurface drainage seems to be a prerequisite for optimal crop production. Considering specific characteristics of the paddies, application of a suitable equation for planning of subsurface drainage systems is of great importance. In this study, five steady-state equations including Hooghoudt, Kirkham, Dagan, Ernst, and Ernst–Hooghoudt; and three unsteady-state equations including Glover–Dumm, Van-Shilfgard, and De-zeeuw–Hellinga were implemented to compute drain spacing. Required field data were obtained from 52 ha of paddy fields of “Haraz Human-Agriculture Resources Development Center,” located in Mazandaran province of Iran. The computed drain spacings were evaluated using dynamic equilibrium concept and DRAINMOD model. The minimum and maximum drain spacings were found to be 26 and 63 m corresponding to Glover–Dumm and Ernst equations, respectively. Based on the dynamic equilibrium concept, the averages of the computed water table depths for the drain spacings obtained by the unsteady-state equations were 0.5–0.63 m as compared with those obtained by the steady-state methods which were in the range of 0–0.43 m. According to the DRAINMOD model simulations, the maximum relative yield was 80.2 % which was obtained when the drain spacing was 26 m and it reduced to 73.5 % when the drain spacing was increased to 63 m. The computed drain spacings suggested by the unsteady-state equations were found to be more suitable than those obtained from the steady-state equations for the study area.

The Impact of Different Levels of Nitrogen Fertigation and Irrigation on Nitrogen Leaching of Corn Silage

2007 Minneapolis, Minnesota, June 17-20, 2007, 2007

Page 1. The authors are solely responsible for the content of this technical presentation. The te... more Page 1. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers ...

Point estimation of soil water infiltration process using Artificial Neural Networks for some calcareous soils

Journal of Hydrology, 2013

ABSTRACT Highlights ► Performance of developed ANN models improved through the infiltration time.... more ABSTRACT Highlights ► Performance of developed ANN models improved through the infiltration time. ► Cumulative infiltration curve, I(t), was estimated with the mean RMSD of 6.307 cm. ► The estimated I(t) can be accepted as a reliable infiltration test result (p < 0.01).

Agronomy Journal, 2013

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or b... more All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.

Weeds – Friend or foe? Increasing forage yield and decreasing nitrate leaching on a corn forage farm infested by redroot pigweed

Agriculture, Ecosystems & Environment, 2013

ABSTRACT a b s t r a c t Various weed management methods have been tested without complete succes... more ABSTRACT a b s t r a c t Various weed management methods have been tested without complete success and still represent a major nuisance often negatively effecting yields. Therefore, it may be time to change attitudes about weeds and view them as friends of the agroecosystem rather than as foes. For the first time, field experi-ments were conducted to introduce and evaluate the yield and quality of corn–redroot pigweed mixture forage in a semi-arid region of Iran during 2010 and 2011. A randomized complete block design with a split factorial arrangement of treatments in four replications was subjected to low irrigation and full irrigation regimes. Subplots consisted of a factorial combination of four N levels (0, 150, 300 and 450 kg N ha −1) and two forage mixtures (corn monoculture and corn–redroot pigweed mixture). When averaged over both years, N addition (from 0 to 450 kg N ha −1) increased corn forage yield by 74 and 42% under full and low irrigation regimes, respectively. The forage yield increased by 121 and 69% in the corn–pigweed mixture for comparable treatments. In corn monoculture, the minimum required for-age protein (90 g kg −1) occurred only where forage yields were lower than 10 t ha −1 , whereas in the corn–pigweed mixture, all the treatments with 90 g kg −1 protein produced yield more than 11 t ha −1 . N enhancement (0–450 kg ha −1) increased nitrate leaching loss (NLL) by 158 and 107 kg ha −1 in corn monoculture and 100 and 55 kg ha −1 in the corn–pigweed mixture under full and low irrigation regimes, respectively. However, an alteration in the NLL trend in response to N application grew in both forage types, but the NLL severity was reduced in the corn pigweed mixture. The integration of redroot pigweed (a major weed species on summer crop farms) with corn, rather than its removal, could be recommended to ensure an acceptable forage yield/quality in a poor sandy soil while also reducing N leaching.

Effect of subsurface drainage on water balance and water table in poorly drained paddy fields

Agricultural Water Management, 2013

ABSTRACT The hydrological effects of different drainage systems were investigated as a pilot stud... more ABSTRACT The hydrological effects of different drainage systems were investigated as a pilot study in 4.5 ha of paddy fields of Sari Agricultural Sciences and Natural Resources University, located at Mazandaran province, Northern Iran (36.3 °N, 53.04 °E), during two successive growing seasons of rice and canola from July 2011 to May 2012. Experimental treatments were: three conventional subsurface drainage systems including drainage system with drain depth of 0.9 m and drain spacing of 30 m (D0.9L30), drain depth of 0.65 m and drain spacing of 30 m (D0.65L30), and drain depth of 0.65 m and drain spacing of 15 m (D0.65L15); a bi-level subsurface drainage system with drain spacing of 15 m and drain depths of 0.65 and 0.9 m as alternate depths (Bilevel), and surface drainage system (Control). Water balance components were determined in both rice and canola crop seasons. Measurements of water table depth and subsurface drainage discharge were made daily during drainage periods. In the rice season, the total water supply was 754.6 mm, of which 61.7% was lost by evapotranspiration and 16.2–19.1% was lost by deep percolation (DP). In the canola season, the treatments of D0.9L30, Bilevel, D0.65L30 and D0.65L15 were discharged, respectively, 44%, 51.5%, 43% and 60.5% of the total rainfall from the soil profile. Shallow drains were more effective in controlling water table compared with deep drains so that, average of measured water table depths in the representative observation wells of D0.9L30, Bilevel, D0.65L30, and D0.65L15 were 2.1, 15, 24.1, and 32.4 cm, respectively. Also, values of SEW30 (sum of excess water) were 3461, 1498, 1038 and 450 cm for D0.9L30, Bilevel, D0.65L30 and D0.65L15, respectively. Based on the results, water management through a subsurface drainage system could provide winter cropping condition in the study area.

Interactions of irrigation, weed and nitrogen on corn yield, nitrogen use efficiency and nitrate leaching

Agricultural Water Management, 2013

ABSTRACT The effects of water, N and weed interactions on crop performance have not been adequate... more ABSTRACT The effects of water, N and weed interactions on crop performance have not been adequately addressed. The main objectives of this study, which was conducted in a semi-arid region of Iran during the 2010 and 2011 growing seasons, were to determine the effects of interactions among irrigation regimes (I), weed competition (W) and N rates on corn yield, dry matter and grain N concentration, N use efficiency and nitrate leaching in a sandy soil. The experiment was carried out using a randomized complete block design with a split factorial arrangement of treatments in four replications. The main plots were subjected to the following irrigation treatments: Low frequency irrigation (I1) and high frequency irrigation (I2). The subplots consisted of a factorial combination of four N levels (0, 150, 300 and 450 kg N ha1) and two levels of redroot pigweed interference with corn (weed free, W0; and weedy, W1). When averaged over both years, the results showed that the enhancement of applied N (0–450 kg N ha−1) increased corn grain yield by 63% with high frequency irrigation and by 25% with low frequency irrigation. Moreover, the results showed that the enhancement of applied N from 0 to 450 kg N ha−1 resulted in a ten- and six-fold increase in nitrate leaching loss (NLL) with the high and low frequency irrigation regimes, respectively. In both the weedy and weed free treatments, the NLL increased, but the NLL intensity decreased in response to the enhancement of applied N in the presence of weeds. The mean comparisons of N use efficiency showed that in the N150 treatment, each kilogram of applied N led to the production of 19 and 14 kg grain ha−1 with high and low frequency irrigation, respectively. In contrast, in the N450 treatment, each kilogram of applied N resulted in the production of 8 and 5 kg grain ha−1 in the high and low frequency irrigation regimes, respectively. Finally, results showed that it is necessary to achieve equilibrium between applied water and N, especially in sandy soils, which will lead to a reduction in the indiscriminate application of nitrogen fertilizer that does not effectively increase the corn yield whereas it severely increases nitrate leaching loss.

Agricultural Water Management, 2009

parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In h... more parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In humid regions, heavy rainfall can cause NO 3 pollution whereas in arid and semi-arid regions (Jalali, 2005) excess irrigation can be the cause. Management and control of NO 3 leaching are difficult because NO 3 losses are often intermittent, and linked with seasonal land management, irrigation practices and fertilizer applications and/or irregular events, such as rain (Carpenter et al., 1998; Barton and Colmer, 2006). A high NO 3 concentration in the root zone is one of the major concerns in extensively irrigated areas, where excess water needs to be applied to control salinity that results in deep percolation, one of the sources of water to recharged groundwater aquifers beneath irrigated lands (Klocke et al., 1993; Watts, 1997). Applying N at a rate less than optimal (Schroder et al., 1998) and/or using a variable deficit irrigation scheduling regime (Sexton et al., 1996) can reduce NO 3 leaching. NO 3 leaching has been studied under different irrigation and fertilizer management regimes for semi-arid and arid climates

Agricultural Water Management, 2009

Water scarcity and environmental pollution due to excessive nitrogen (N) applications are importa... more Water scarcity and environmental pollution due to excessive nitrogen (N) applications are important environmental concerns. The Varamin region, which is located in the central part of Iran, is one of the locations where farmers apply 250-350 kg N ha À1 for silage maize without any concerns with respect to the available water for irrigation. The objective of this study was to quantify the response of the silage maize (Zea mays L.) to variable irrigation and N fertilizer applications under arid and semi-arid conditions and to determine the optimum amount of N fertilizer as a function of irrigation. The maize Hybrid 704 single-cross was planted on 3 August 2003 and on 25 June 2004. The experimental treatments consisted of three N rates (0, 150, and 200 kg N ha À1) and four levels of irrigation, including two deficit irrigation levels 0.70 SWD (soil water depletion) and 0.85 SWD, a full-irrigation level (1.0 SWD) and an over-irrigation level (1.13 SWD). Twelve treatments were arranged in a strip-* Corresponding author.

Precise estimate of evapotranspiration (ET) or crop water requirements crucial for improving wate... more Precise estimate of evapotranspiration (ET) or crop water requirements crucial for improving water resources management and eventually increasing water use efficiency. Considering the vast varieties of crops cultivated on large scales, calculating precisely the crop water requirement from ordinary methods of estimating reference evapotranspiration is difficult and in some cases even impossible. Therefore, it is necessary to develop methods to compute crop water requirement in large areas with sufficient accuracy. One of such methods is to use remote sensing data which covers a much larger areas as compared with methods depending on field weather data. One of the most well known methods to compute actual ET from remote sensing data is SEBAL method (Surface Energy Balance Algorithm on Land). In SEBAL method, all fluxes of the energy balance at the earth's surface including net radiation, soil heat flux, and sensible heat flux are calculated from satellite images and finally actual ET is computed based on the energy balance at the earth's surface. It is intended to evaluate spatio-temporal variation of daily ET in Mirza Kochakkhan sugarcane Agro-Industry farms located in southern part of the Khosetan province using MODIS images for 10-day periods during a growing season in 2006-2007. The results obtained indicated that the SEBAL method was an efficient method to estimate actual ET during the growing season. Maps of actual ET generated by ERDAS and GIS software showed that fields which were well irrigated or had a good crop cover had the highest values of ET. However, actual ET decreased for areas with less crop cover or dry fields. The data obtained from the generated maps of actual ET were closer to the data obtained from the field with a coefficient of determination of R 2 =0.77.

Evaluating Silage Maize Production Under Pulsed Drip Irrigation

SSRN Electronic Journal

Producing daily actual evapotranspiration (ETa) maps with high spatial resolution has always been... more Producing daily actual evapotranspiration (ETa) maps with high spatial resolution has always been a challenge for remote sensing research. This study assessed the feasibility of producing daily ETa maps with a high spatial resolution (30 m) for the sugarcane farmlands of Amir Kabir Sugarcane Agro-industry (Khuzestan, Iran) using three different scenarios. In the first scenario, the reflectance bands of Landsat 8 were predicted from the moderate resolution imaging spectroradiometer (MODIS) imagery using the spatial and temporal adaptive reflectance fusion model (STARFM) algorithm. Also, the thermal bands of Landsat 8 were predicted by the spatiotemporal adaptive data fusion algorithm for temperature mapping (SADFAT). Then, ETa amounts were calculated employing such bands and the surface energy balance algorithm for land (SEBAL). In the second scenario, the input data needed by SEBAL were downscaled using the MODIS images and different methods. Then, using the downscaled data and SEBA...

Journal of Plant Nutrition

Knowing the concentrations of the nutrient elements in soils is important due to their toxic effe... more Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split Split Plot design based on the Randomized complete Block (RCB) with two treatments (well's and wastewater), and eight subtreatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy-loam soil, in Shahrekord, Iran. Soil samples were collected from 0-30 and 30-60 cm depth for measuring nitrate (NO 3-), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform (FC) were also measured at the soil Keywords Soil chemical properties, Subsurface drip irrigation, Wastewater and dripper installation depth.

Agricultural Water Management an International Journal, Jun 1, 2009

parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In h... more parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In humid regions, heavy rainfall can cause NO 3 pollution whereas in arid and semi-arid regions (Jalali, 2005) excess irrigation can be the cause. Management and control of NO 3 leaching are difficult because NO 3 losses are often intermittent, and linked with seasonal land management, irrigation practices and fertilizer applications and/or irregular events, such as rain (Carpenter et al., 1998; Barton and Colmer, 2006). A high NO 3 concentration in the root zone is one of the major concerns in extensively irrigated areas, where excess water needs to be applied to control salinity that results in deep percolation, one of the sources of water to recharged groundwater aquifers beneath irrigated lands (Klocke et al., 1993; Watts, 1997). Applying N at a rate less than optimal (Schroder et al., 1998) and/or using a variable deficit irrigation scheduling regime (Sexton et al., 1996) can reduce NO 3 leaching. NO 3 leaching has been studied under different irrigation and fertilizer management regimes for semi-arid and arid climates

Diurnal variations of photosynthetic gas exchanges in two Iranian pistachio (Pistacia vera L.) genotypes

Diurnal variations of net photosynthesis (A), stomatal conductance (gs) and transpiration (E) rat... more Diurnal variations of net photosynthesis (A), stomatal conductance (gs) and transpiration (E) rates were assessed at the leaf surfaces of two pistachio (Pistacia vera L.) genotypes, in reference to diurnal fluctuations of leaf temperature (Tleaf), vapor pressure deficit (VPD) and photosynthetic photon flux density (PPFD). In this experiment, diurnal changes of net CO2 assimilation showed a two-peak pattern in which the first peaks were appeared at 9:00 and 8:00 in ‘Badami’ and ‘Qazvini’ genotypes, respectively. Also, the second peaks emerged at 16:00, and the lowest assimilation rates were observed at 15:00 in both genotypes. The corresponded PPFD with the highest net assimilation rate were achieved at 1500 and 1150 µmol m-2 s-1 in ‘Badami’ and ‘Qazvini’, respectively. Diurnal pattern of net photosynthesis rates was correlated with stomatal conductance ¬(r=0.76) and transpiration (r=0.73) rates. It seems that stomatal conductance in 'Badami' was primarily limited by VPD and ...

Comparison of steady- and unsteady-state drainage equations for determination of subsurface drain spacing in paddy fields: a case study in Northern Iran

Paddy and Water Environment, 2013

ABSTRACT In Northern Iran paddy fields, waterlogging is a serious problem. Provision of subsurfac... more ABSTRACT In Northern Iran paddy fields, waterlogging is a serious problem. Provision of subsurface drainage seems to be a prerequisite for optimal crop production. Considering specific characteristics of the paddies, application of a suitable equation for planning of subsurface drainage systems is of great importance. In this study, five steady-state equations including Hooghoudt, Kirkham, Dagan, Ernst, and Ernst–Hooghoudt; and three unsteady-state equations including Glover–Dumm, Van-Shilfgard, and De-zeeuw–Hellinga were implemented to compute drain spacing. Required field data were obtained from 52 ha of paddy fields of “Haraz Human-Agriculture Resources Development Center,” located in Mazandaran province of Iran. The computed drain spacings were evaluated using dynamic equilibrium concept and DRAINMOD model. The minimum and maximum drain spacings were found to be 26 and 63 m corresponding to Glover–Dumm and Ernst equations, respectively. Based on the dynamic equilibrium concept, the averages of the computed water table depths for the drain spacings obtained by the unsteady-state equations were 0.5–0.63 m as compared with those obtained by the steady-state methods which were in the range of 0–0.43 m. According to the DRAINMOD model simulations, the maximum relative yield was 80.2 % which was obtained when the drain spacing was 26 m and it reduced to 73.5 % when the drain spacing was increased to 63 m. The computed drain spacings suggested by the unsteady-state equations were found to be more suitable than those obtained from the steady-state equations for the study area.

The Impact of Different Levels of Nitrogen Fertigation and Irrigation on Nitrogen Leaching of Corn Silage

2007 Minneapolis, Minnesota, June 17-20, 2007, 2007

Page 1. The authors are solely responsible for the content of this technical presentation. The te... more Page 1. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers ...

Point estimation of soil water infiltration process using Artificial Neural Networks for some calcareous soils

Journal of Hydrology, 2013

ABSTRACT Highlights ► Performance of developed ANN models improved through the infiltration time.... more ABSTRACT Highlights ► Performance of developed ANN models improved through the infiltration time. ► Cumulative infiltration curve, I(t), was estimated with the mean RMSD of 6.307 cm. ► The estimated I(t) can be accepted as a reliable infiltration test result (p < 0.01).

Agronomy Journal, 2013

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or b... more All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.

Weeds – Friend or foe? Increasing forage yield and decreasing nitrate leaching on a corn forage farm infested by redroot pigweed

Agriculture, Ecosystems & Environment, 2013

ABSTRACT a b s t r a c t Various weed management methods have been tested without complete succes... more ABSTRACT a b s t r a c t Various weed management methods have been tested without complete success and still represent a major nuisance often negatively effecting yields. Therefore, it may be time to change attitudes about weeds and view them as friends of the agroecosystem rather than as foes. For the first time, field experi-ments were conducted to introduce and evaluate the yield and quality of corn–redroot pigweed mixture forage in a semi-arid region of Iran during 2010 and 2011. A randomized complete block design with a split factorial arrangement of treatments in four replications was subjected to low irrigation and full irrigation regimes. Subplots consisted of a factorial combination of four N levels (0, 150, 300 and 450 kg N ha −1) and two forage mixtures (corn monoculture and corn–redroot pigweed mixture). When averaged over both years, N addition (from 0 to 450 kg N ha −1) increased corn forage yield by 74 and 42% under full and low irrigation regimes, respectively. The forage yield increased by 121 and 69% in the corn–pigweed mixture for comparable treatments. In corn monoculture, the minimum required for-age protein (90 g kg −1) occurred only where forage yields were lower than 10 t ha −1 , whereas in the corn–pigweed mixture, all the treatments with 90 g kg −1 protein produced yield more than 11 t ha −1 . N enhancement (0–450 kg ha −1) increased nitrate leaching loss (NLL) by 158 and 107 kg ha −1 in corn monoculture and 100 and 55 kg ha −1 in the corn–pigweed mixture under full and low irrigation regimes, respectively. However, an alteration in the NLL trend in response to N application grew in both forage types, but the NLL severity was reduced in the corn pigweed mixture. The integration of redroot pigweed (a major weed species on summer crop farms) with corn, rather than its removal, could be recommended to ensure an acceptable forage yield/quality in a poor sandy soil while also reducing N leaching.

Effect of subsurface drainage on water balance and water table in poorly drained paddy fields

Agricultural Water Management, 2013

ABSTRACT The hydrological effects of different drainage systems were investigated as a pilot stud... more ABSTRACT The hydrological effects of different drainage systems were investigated as a pilot study in 4.5 ha of paddy fields of Sari Agricultural Sciences and Natural Resources University, located at Mazandaran province, Northern Iran (36.3 °N, 53.04 °E), during two successive growing seasons of rice and canola from July 2011 to May 2012. Experimental treatments were: three conventional subsurface drainage systems including drainage system with drain depth of 0.9 m and drain spacing of 30 m (D0.9L30), drain depth of 0.65 m and drain spacing of 30 m (D0.65L30), and drain depth of 0.65 m and drain spacing of 15 m (D0.65L15); a bi-level subsurface drainage system with drain spacing of 15 m and drain depths of 0.65 and 0.9 m as alternate depths (Bilevel), and surface drainage system (Control). Water balance components were determined in both rice and canola crop seasons. Measurements of water table depth and subsurface drainage discharge were made daily during drainage periods. In the rice season, the total water supply was 754.6 mm, of which 61.7% was lost by evapotranspiration and 16.2–19.1% was lost by deep percolation (DP). In the canola season, the treatments of D0.9L30, Bilevel, D0.65L30 and D0.65L15 were discharged, respectively, 44%, 51.5%, 43% and 60.5% of the total rainfall from the soil profile. Shallow drains were more effective in controlling water table compared with deep drains so that, average of measured water table depths in the representative observation wells of D0.9L30, Bilevel, D0.65L30, and D0.65L15 were 2.1, 15, 24.1, and 32.4 cm, respectively. Also, values of SEW30 (sum of excess water) were 3461, 1498, 1038 and 450 cm for D0.9L30, Bilevel, D0.65L30 and D0.65L15, respectively. Based on the results, water management through a subsurface drainage system could provide winter cropping condition in the study area.

Interactions of irrigation, weed and nitrogen on corn yield, nitrogen use efficiency and nitrate leaching

Agricultural Water Management, 2013

ABSTRACT The effects of water, N and weed interactions on crop performance have not been adequate... more ABSTRACT The effects of water, N and weed interactions on crop performance have not been adequately addressed. The main objectives of this study, which was conducted in a semi-arid region of Iran during the 2010 and 2011 growing seasons, were to determine the effects of interactions among irrigation regimes (I), weed competition (W) and N rates on corn yield, dry matter and grain N concentration, N use efficiency and nitrate leaching in a sandy soil. The experiment was carried out using a randomized complete block design with a split factorial arrangement of treatments in four replications. The main plots were subjected to the following irrigation treatments: Low frequency irrigation (I1) and high frequency irrigation (I2). The subplots consisted of a factorial combination of four N levels (0, 150, 300 and 450 kg N ha1) and two levels of redroot pigweed interference with corn (weed free, W0; and weedy, W1). When averaged over both years, the results showed that the enhancement of applied N (0–450 kg N ha−1) increased corn grain yield by 63% with high frequency irrigation and by 25% with low frequency irrigation. Moreover, the results showed that the enhancement of applied N from 0 to 450 kg N ha−1 resulted in a ten- and six-fold increase in nitrate leaching loss (NLL) with the high and low frequency irrigation regimes, respectively. In both the weedy and weed free treatments, the NLL increased, but the NLL intensity decreased in response to the enhancement of applied N in the presence of weeds. The mean comparisons of N use efficiency showed that in the N150 treatment, each kilogram of applied N led to the production of 19 and 14 kg grain ha−1 with high and low frequency irrigation, respectively. In contrast, in the N450 treatment, each kilogram of applied N resulted in the production of 8 and 5 kg grain ha−1 in the high and low frequency irrigation regimes, respectively. Finally, results showed that it is necessary to achieve equilibrium between applied water and N, especially in sandy soils, which will lead to a reduction in the indiscriminate application of nitrogen fertilizer that does not effectively increase the corn yield whereas it severely increases nitrate leaching loss.

Agricultural Water Management, 2009

parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In h... more parts of the world under a broad spectrum of climatic conditions: humid, semi-arid and arid. In humid regions, heavy rainfall can cause NO 3 pollution whereas in arid and semi-arid regions (Jalali, 2005) excess irrigation can be the cause. Management and control of NO 3 leaching are difficult because NO 3 losses are often intermittent, and linked with seasonal land management, irrigation practices and fertilizer applications and/or irregular events, such as rain (Carpenter et al., 1998; Barton and Colmer, 2006). A high NO 3 concentration in the root zone is one of the major concerns in extensively irrigated areas, where excess water needs to be applied to control salinity that results in deep percolation, one of the sources of water to recharged groundwater aquifers beneath irrigated lands (Klocke et al., 1993; Watts, 1997). Applying N at a rate less than optimal (Schroder et al., 1998) and/or using a variable deficit irrigation scheduling regime (Sexton et al., 1996) can reduce NO 3 leaching. NO 3 leaching has been studied under different irrigation and fertilizer management regimes for semi-arid and arid climates

Agricultural Water Management, 2009

Water scarcity and environmental pollution due to excessive nitrogen (N) applications are importa... more Water scarcity and environmental pollution due to excessive nitrogen (N) applications are important environmental concerns. The Varamin region, which is located in the central part of Iran, is one of the locations where farmers apply 250-350 kg N ha À1 for silage maize without any concerns with respect to the available water for irrigation. The objective of this study was to quantify the response of the silage maize (Zea mays L.) to variable irrigation and N fertilizer applications under arid and semi-arid conditions and to determine the optimum amount of N fertilizer as a function of irrigation. The maize Hybrid 704 single-cross was planted on 3 August 2003 and on 25 June 2004. The experimental treatments consisted of three N rates (0, 150, and 200 kg N ha À1) and four levels of irrigation, including two deficit irrigation levels 0.70 SWD (soil water depletion) and 0.85 SWD, a full-irrigation level (1.0 SWD) and an over-irrigation level (1.13 SWD). Twelve treatments were arranged in a strip-* Corresponding author.