International Journal of Agriculture: Research and Review, 2013
ABSTRACT Understanding the quality condition and it's variation pattern play an important... more ABSTRACT Understanding the quality condition and it's variation pattern play an important role in future planning and appropriate management of water resources and this requires availability of data related to location, amount and distribution of chemical factors of water in a given geographical region; thus processing and analysis of such data should be implemented by considering their spatial location related to each other, and therefore geostatistics is used as a technique for this purpose. The aim of this research is to determine the most suitable interpolation method in order to assessment and spatial analysis of parameters Cl, Na and TH in groundwater in Shahr-e Babak (located at western part of Kerman province). For this purpose, the common geostatistical methods such as ordinary kriging, universal kriging and deterministic methods including IDW, GPI, LPI and RBF were used. Results showed that from deterministic methods, RBF due to having lower RMSE and MAE is more suitable to develop the variation map of parameters Cl, Na and TH. Also, from common geostatistical methods, ordinary kriging is the best one. Finally, by comparing various interpolation methods it was concluded that, simple kriging method was superior to other deterministic and common geostatistical methods and it was selected as the suitable method to develop final map of variation of parameters Cl, Na and TH in Shahr-e Babak plain.
Degree Doctor of Philosophy, Ohio State University, Soil Science, 2010 . Abstract In Ohio, approx... more Degree Doctor of Philosophy, Ohio State University, Soil Science, 2010 . Abstract In Ohio, approximately 55% of agricultural land needs drainage to overcome occasional water ponding, reduce soil erosion, improve fields to support farm equipment and reduce crop yield variability. In ...
Sweet oranges in Puerto Rico and other citrus-producing areas in the world have been greatly affe... more Sweet oranges in Puerto Rico and other citrus-producing areas in the world have been greatly affected by the Huanglongbing disease (HLB). Historically, most of Puerto Rico’s citrus production has been located from 0–600 m above sea level, where fruit acquire a desirable color and flavor due to climatic conditions. However, higher populations of the disease vector Diaphorina citri Kuwayama have been reported at these elevations in Puerto Rico. Although only 6.4% of the land area is located above 600 m, it is composed mainly of environmentally sensitive or non-arable land where Inceptisols are the dominant soil order. For that reason, ‘Marr’s Early’ and ‘Pera’ sweet orange (Citrus sinensis) scions grafted on ‘Carrizo’, ‘HRS 802’, and ‘HRS 812’ rootstocks were planted in Alonso clay series Inceptisol (Oxic Humudepts) at 649 m in 2010. Tree growth parameters (height, diameter, canopy volume) and yield efficiency were measured. Fruit quality was determined from juice content (%), total s...
Hydrology and Earth System Sciences Discussions, 2014
Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are... more Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in tropical environments. We measured ET (ET<sub>EC</sub>) using Eddy Covariance (EC) towers at two irrigated sugarcane fields on the leeward (dry) side of Maui, Hawaii, USA in contrasting climates. We calculated reference ET at the fields using the short (ET<sub>0</sub>) and tall (ET<sub>r</sub>) vegetation versions of the American Society for Civil Engineers (ASCE) equation. The ASCE equations were compared to the Priestley–Taylor ET (ET<sub>PT</sub>) and ET<sub>EC</sub>. Reference ET from the ASCE approaches exceeded ET<sub>EC</sub> during the mid-period (when vegetation coefficients suggest ET<sub>EC</sub> should exceed reference ET). At the windier tower site, cumulative ET<sub>r...
Journal of Agriculture of The University of Puerto Rico, 2017
Pineapple [Ananas comosus (L.) Mere] is an important fruit crop cultivated in many tropical count... more Pineapple [Ananas comosus (L.) Mere] is an important fruit crop cultivated in many tropical countries. This fruit crop requires large amounts of nitrogen (N) and potassium (K) to maximize yield. Although pineapple has low water requirements, extended drought can affect yield. Two experiments were conducted to study the effects of fertilizer application methods and drip irrigation management on pineapple yields. Pineapple cultivars MD-2 and Cabezona were planted at Isabela and Lajas, Puerto Rico, respectively. Fertilizer and irrigation treatments included: i) Controlapplication of 896 kg/ha of a granular fertilizer (12-6-10-3) at two, five and nine months after planting; ii) FS-R- application of 150-150-120-45 kg/ha at planting plus 20 foliar applications of urea and potassium sulfate (50 kg/ha) every three weeks, rainfed; iii) FS-DI- application of 150-150-120-45 kg/ha at planting plus 20 foliar applications of urea and potassium sulfate (50 kg/ha), drip irrigation applied every three weeks; iv) FERT- application of 150-150-120-45 kg/ha at planting, but urea and potassium sulfate (50 kg/ha) were applied throughout fertigation; and v) CRF- same amount of nutrients as FS-R but N was applied as a controlled release fertilizer every six months. At Isabela, treatment FS-R produced the highest fruit weight (2.5 kg per fruit) and 1.5% of N in tissue, but did not differ significantly from FS-DI and CRF. Plants under CRF registered the highest Brix (15.8°). Although foliar fertilizer tended to produce higher yields, controlled release fertilizer is recommended because it eliminates the need for frequent foliar application without compromising yield.
The Journal of Agriculture of the University of Puerto Rico, 2021
Irrigation scheduling (IS) and fertilization are among the most important practices in the produc... more Irrigation scheduling (IS) and fertilization are among the most important practices in the production of horticultural crops because they affect fruit quality and quantity directly. Thus, a 15-year-old avocado orchard (cv. ‘Simmonds’) was used to determine precise IS, based on monitoring soil moisture content (SMC), remote sensing technologies [Unmanned Aerial Vehicle (UAV)] under two fertilization levels using granular formulation 15-3-19. In October 2015, all trees were pruned (topped and hedged) to 3.05 m height and 2.44 m diameter. In December 2015, soil moisture (SM) sensors were installed at five (10, 30, 50, 70 and 90 cm) soil depths in six locations. Trees received two fertilizer treatments: F1-9.06 kg and F2-12.07 kg of 15-3-19/tree/year every three months. Precipitation and SM data were recorded daily for 21 months; SM data was corrected with a quadratic equation (y = -4.1881x2 + 3.6886x - 0.3083) generated specifically for the Coto soil series (Typic Hapludox). The SM val...
Since Huanglongbing (HLB) disease was detected in 2009 in Puerto Rico, a steady drop in citrus pr... more Since Huanglongbing (HLB) disease was detected in 2009 in Puerto Rico, a steady drop in citrus production has been experienced, forcing farmers to abandon their land or switch to other crops. Between 2015 and 2016, we used grafted trees from two experimental orchards (Tahiti lime and Nova mandarin), each on five rootstocks, to collect soil and plant tissue samples from each scion‒rootstock combination to determine soil fertility, tissue nutrient content, and yield. The tree growth parameters (height, diameter, and canopy volume) and efficiency of the two orchards were also measured. These orchards, growing in Coto series (Typic Hapludox), were planted in 2009 and reported as heavily infested with HLB by 2011. Our results showed that soil and tissue samples from the Tahiti lime orchard exhibited benefits for tree growth parameters when grafted on Carrizo and Cleopatra rootstocks. Lower tree mortality (13%) was observed for Tahiti lime grafted on Carrizo, HRS 812, Carrizo and Rough le...
International Journal of Agriculture: Research and Review, 2013
ABSTRACT Understanding the quality condition and it&#39;s variation pattern play an important... more ABSTRACT Understanding the quality condition and it&#39;s variation pattern play an important role in future planning and appropriate management of water resources and this requires availability of data related to location, amount and distribution of chemical factors of water in a given geographical region; thus processing and analysis of such data should be implemented by considering their spatial location related to each other, and therefore geostatistics is used as a technique for this purpose. The aim of this research is to determine the most suitable interpolation method in order to assessment and spatial analysis of parameters Cl, Na and TH in groundwater in Shahr-e Babak (located at western part of Kerman province). For this purpose, the common geostatistical methods such as ordinary kriging, universal kriging and deterministic methods including IDW, GPI, LPI and RBF were used. Results showed that from deterministic methods, RBF due to having lower RMSE and MAE is more suitable to develop the variation map of parameters Cl, Na and TH. Also, from common geostatistical methods, ordinary kriging is the best one. Finally, by comparing various interpolation methods it was concluded that, simple kriging method was superior to other deterministic and common geostatistical methods and it was selected as the suitable method to develop final map of variation of parameters Cl, Na and TH in Shahr-e Babak plain.
Degree Doctor of Philosophy, Ohio State University, Soil Science, 2010 . Abstract In Ohio, approx... more Degree Doctor of Philosophy, Ohio State University, Soil Science, 2010 . Abstract In Ohio, approximately 55% of agricultural land needs drainage to overcome occasional water ponding, reduce soil erosion, improve fields to support farm equipment and reduce crop yield variability. In ...
Sweet oranges in Puerto Rico and other citrus-producing areas in the world have been greatly affe... more Sweet oranges in Puerto Rico and other citrus-producing areas in the world have been greatly affected by the Huanglongbing disease (HLB). Historically, most of Puerto Rico’s citrus production has been located from 0–600 m above sea level, where fruit acquire a desirable color and flavor due to climatic conditions. However, higher populations of the disease vector Diaphorina citri Kuwayama have been reported at these elevations in Puerto Rico. Although only 6.4% of the land area is located above 600 m, it is composed mainly of environmentally sensitive or non-arable land where Inceptisols are the dominant soil order. For that reason, ‘Marr’s Early’ and ‘Pera’ sweet orange (Citrus sinensis) scions grafted on ‘Carrizo’, ‘HRS 802’, and ‘HRS 812’ rootstocks were planted in Alonso clay series Inceptisol (Oxic Humudepts) at 649 m in 2010. Tree growth parameters (height, diameter, canopy volume) and yield efficiency were measured. Fruit quality was determined from juice content (%), total s...
Hydrology and Earth System Sciences Discussions, 2014
Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are... more Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in tropical environments. We measured ET (ET<sub>EC</sub>) using Eddy Covariance (EC) towers at two irrigated sugarcane fields on the leeward (dry) side of Maui, Hawaii, USA in contrasting climates. We calculated reference ET at the fields using the short (ET<sub>0</sub>) and tall (ET<sub>r</sub>) vegetation versions of the American Society for Civil Engineers (ASCE) equation. The ASCE equations were compared to the Priestley–Taylor ET (ET<sub>PT</sub>) and ET<sub>EC</sub>. Reference ET from the ASCE approaches exceeded ET<sub>EC</sub> during the mid-period (when vegetation coefficients suggest ET<sub>EC</sub> should exceed reference ET). At the windier tower site, cumulative ET<sub>r...
Journal of Agriculture of The University of Puerto Rico, 2017
Pineapple [Ananas comosus (L.) Mere] is an important fruit crop cultivated in many tropical count... more Pineapple [Ananas comosus (L.) Mere] is an important fruit crop cultivated in many tropical countries. This fruit crop requires large amounts of nitrogen (N) and potassium (K) to maximize yield. Although pineapple has low water requirements, extended drought can affect yield. Two experiments were conducted to study the effects of fertilizer application methods and drip irrigation management on pineapple yields. Pineapple cultivars MD-2 and Cabezona were planted at Isabela and Lajas, Puerto Rico, respectively. Fertilizer and irrigation treatments included: i) Controlapplication of 896 kg/ha of a granular fertilizer (12-6-10-3) at two, five and nine months after planting; ii) FS-R- application of 150-150-120-45 kg/ha at planting plus 20 foliar applications of urea and potassium sulfate (50 kg/ha) every three weeks, rainfed; iii) FS-DI- application of 150-150-120-45 kg/ha at planting plus 20 foliar applications of urea and potassium sulfate (50 kg/ha), drip irrigation applied every three weeks; iv) FERT- application of 150-150-120-45 kg/ha at planting, but urea and potassium sulfate (50 kg/ha) were applied throughout fertigation; and v) CRF- same amount of nutrients as FS-R but N was applied as a controlled release fertilizer every six months. At Isabela, treatment FS-R produced the highest fruit weight (2.5 kg per fruit) and 1.5% of N in tissue, but did not differ significantly from FS-DI and CRF. Plants under CRF registered the highest Brix (15.8°). Although foliar fertilizer tended to produce higher yields, controlled release fertilizer is recommended because it eliminates the need for frequent foliar application without compromising yield.
The Journal of Agriculture of the University of Puerto Rico, 2021
Irrigation scheduling (IS) and fertilization are among the most important practices in the produc... more Irrigation scheduling (IS) and fertilization are among the most important practices in the production of horticultural crops because they affect fruit quality and quantity directly. Thus, a 15-year-old avocado orchard (cv. ‘Simmonds’) was used to determine precise IS, based on monitoring soil moisture content (SMC), remote sensing technologies [Unmanned Aerial Vehicle (UAV)] under two fertilization levels using granular formulation 15-3-19. In October 2015, all trees were pruned (topped and hedged) to 3.05 m height and 2.44 m diameter. In December 2015, soil moisture (SM) sensors were installed at five (10, 30, 50, 70 and 90 cm) soil depths in six locations. Trees received two fertilizer treatments: F1-9.06 kg and F2-12.07 kg of 15-3-19/tree/year every three months. Precipitation and SM data were recorded daily for 21 months; SM data was corrected with a quadratic equation (y = -4.1881x2 + 3.6886x - 0.3083) generated specifically for the Coto soil series (Typic Hapludox). The SM val...
Since Huanglongbing (HLB) disease was detected in 2009 in Puerto Rico, a steady drop in citrus pr... more Since Huanglongbing (HLB) disease was detected in 2009 in Puerto Rico, a steady drop in citrus production has been experienced, forcing farmers to abandon their land or switch to other crops. Between 2015 and 2016, we used grafted trees from two experimental orchards (Tahiti lime and Nova mandarin), each on five rootstocks, to collect soil and plant tissue samples from each scion‒rootstock combination to determine soil fertility, tissue nutrient content, and yield. The tree growth parameters (height, diameter, and canopy volume) and efficiency of the two orchards were also measured. These orchards, growing in Coto series (Typic Hapludox), were planted in 2009 and reported as heavily infested with HLB by 2011. Our results showed that soil and tissue samples from the Tahiti lime orchard exhibited benefits for tree growth parameters when grafted on Carrizo and Cleopatra rootstocks. Lower tree mortality (13%) was observed for Tahiti lime grafted on Carrizo, HRS 812, Carrizo and Rough le...
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