Institute of Soils

Beit Jann, Israel

Institute of Soils

Beit Jann, Israel

Time filter

Source Type

Zhang W.-P.,China Agricultural University | Liu G.-C.,China Agricultural University | Sun J.-H.,Institute of Soils | Fornara D.,Bt Inc. | And 3 more authors.
Functional Ecology | Year: 2016

The productivity of species-diverse plant assemblages strongly depends on the temporal dynamics of nutrient uptake by competing neighbouring plants. Our understanding, however, of how rates of nitrogen (N), phosphorous (P) and potassium (K) uptake might change through time between neighbouring plant species under field conditions is still very limited. Here, we specifically measure the temporal trajectories of N, P and K uptake by staple food plants such as wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and maize (Zea mays L.) when growing either in monocultures or in intercropping systems. We ask how (i) plant species combinations, (ii) N fertilization and (iii) film mulching might affect key indexes of N, P and K uptake over time. We fit logistic models to characterize the nutrient uptake trajectories. Maximum cumulative N, P and K uptake (kg ha-1) by wheat and barley were significantly greater in wheat-maize or barley-maize intercropping systems than in wheat or barley monocultures. Cumulative nutrient uptake by intercropped maize (either with wheat or with barley) was reduced by interspecific competition at early growth stages, but it increased rapidly after wheat and barley were harvested. Maximum cumulative N and P (but not K) uptake by intercropped maize were significantly higher than the uptake by monoculture maize, particularly when N fertilizer or film mulching was applied. Intercropping induced a significant temporal niche differentiation in maximum daily nutrient uptake rates (kg ha-1 day-1) between intercropped species. Fertilization had much stronger effects on maximum cumulative nutrient uptake of maize than that of wheat and barley. Mulching significantly increased the maximum cumulative nutrient uptake of maize and advanced the time to reach its maximum daily P and K uptake rates. Our study provides evidence of an important temporal niche differentiation mechanism ('temporal complementarity') in nutrient uptake rates between neighbouring plant species. A better understanding of temporal trajectories of interspecific nutrient uptake rates remains crucial if we want to maximize the nutrient-use efficiency and sustain overyielding (i.e. high food production) in plant species-diverse systems such as intercropping. © 2016 British Ecological Society.


Zentner E.,Ben - Gurion University of the Negev | Gerstl Z.,Institute of Soils | Weisbrod N.,Ben - Gurion University of the Negev | Lev O.,Hebrew University of Jerusalem | And 5 more authors.
Vadose Zone Journal | Year: 2015

Six boreholes were drilled during the course of a year to a depth of 2 m beneath the water table, located at a depth of about 28 m, under agricultural land sprinkler irrigated with treated sewage effluents in the Coastal Plain aquifer of Israel to determine the extent of penetration of 20 pharmaceuticals and personal care products (PPCPs) into the unsaturated zone. The fields were planted to turf and had different histories of effluent irrigation. From each borehole, 7 to 21 samples were taken for analysis of PPCPs, as was the underlying groundwater. Nine PPCPs (carbamazepine and its metabolite 10-hydroxy-10,11-dihydrocarbamazepine, acridone and acridine, venlafaxine, sulfamethoxazole, oxcarbazepine, O-desmethylvenlafaxine, and caffeine) were detected in the vadose zone of the study area to a depth of 27 m. For example, the detected concentrations of carbamazepine were up to 109 ng/kg, of caffeine up to 36,700 ng/kg, and of venlafaxine up to 50 ng/kg. Only five of the compounds (carbamazepine, acridone, venlafaxine, sulfamethoxazole, and caffeine) were found in the underlying groundwater with concentrations in the nanogram per liter range. The results of this work show that significant amounts of PPCPs can penetrate even a thick vadose zone of 27 m with sections containing up to 50% clay and up to 0.40% soil organic C. Venlafaxine, for example, penetrated the vadose zone at an average velocity of 2.8 to 4 m/yr. Irrigation with treated sewage effluents or contaminated water should be carefully considered if the penetration of PPCPs into groundwater is undesirable. © Soil Science Society of America.


Stanhill G.,Institute of Soils | Achiman O.,Institute of Soils
International Journal of Climatology | Year: 2016

Measurements of global radiation Eg↓ made in the first half of the 20th century are reviewed. The thermoelectric pyranometers used to measure Eg↓ in the United States, Western Europe and Russia are described and the published sources of data available up to and including the 1957 International Geophysical Year are documented together with the few analyses of this data which have been reported. Two 100-year-long series measured at Potsdam, Germany and Washington, DC in the United States are presented to illustrate the potential value of the early measurements in understanding the changes in Eg↓ which have occurred in the last 60 years. © 2016 Royal Meteorological Society.


Addressed here are bimodal, heterogeneous, variably saturated formations, viewed as mixtures of two populations (background soil and embedded soil) of differing spatial structures. Two distinct cases are considered: In the first case, the texture of the embedded soil is finer than that of the background soil; in the second case, the reverse is true. First-order, Lagrangian- stochastic analysis of vadose-zone transport was used to investigate the combined effect of the texture of the embedded soil and the mean pressure head on solute spread and breakthrough in these formations. The main results of the first-order analysis suggest that features of solute transport associated with the two different formations exhibit a crossover behavior and that the mean pressure head associated with the crossover may be estimated from the asymptotic macrodispersivities associated with the two formations. The applicability of the results of the first-order analysis to more realistic conditions was tested with a series of detailed numerical simulations of the flow and transport in three-dimensional, heterogeneous, bimodal, variably saturated formations; relatively simple, steady state flow and more complicated, transient, nonmonotone flow originating from periodic influx and water uptake by plant roots were considered. For the steady state flows, results of the simulations were in qualitative agreement with the results of the first-order analysis. For the more realistic flow regime, the results of the simulations suggested that the difference between the responses of the two different bimodal formations might decrease substantially, similar to the situation in steady state flow associated with mean pressure head at which a crossover occurs. Copyright © 2010 by the American Geophysical Union.


Samara M.,Institute of Soils | Nasser A.,Institute of Soils | Mingelgrin U.,Institute of Soils
Chemosphere | Year: 2016

Carbamazepine (CBZ) is a drug used for treating epilepsy, neuropathic pain, schizophrenia and bipolar disorder. Its widespread use is indicated by its listing in the WHO's Model List of Essential Medicines. The accumulation of CBZ in various environmental compartments, specifically in crops irrigated with treated effluent or grown on soils containing biosolids, is often reported. Being a persistent PPCP (a pharmaceutical and personal care product), developing procedures to remove CBZ is of great importance. In the present study, the breakdown of CBZ by surface reactions in contact with various minerals was attempted. While Al-montmorillonite enhanced CBZ disappearance without the need to apply mechanical force, the efficiency of magnetite in enhancing the disappearance increased considerably upon applying such force. Ball milling with magnetite generated a virtually complete disappearance of CBZ (∼94% of the applied CBZ disappeared after milling for 30 min). HPLC, LC/MS and FTIR were employed in an attempt to elucidate the rate of disappearance and degradation mechanisms of CBZ. A small amount of the hydrolysis product iminostilbene was identified by LC/MS and the breaking off of carbamic acid from the fused rings skeleton of CBZ was indicated by FTIR spectroscopy, confirming the formation of iminostilbene. © 2016 Elsevier Ltd


Ben-Hur M.,Institute of Soils
International Water and Irrigation | Year: 2012

Meni Ben-Hur shares his views on some of the changes, challenges and achievements of the water system in the Israeli agriculture. One of the possibilities to dispose of treated wastewater is its reuse in irrigation. This reuse of treated wastewater in Israeli agriculture has increased and expanded over a period of time. The master plan of the Water Authority estimates that the amounts of treated wastewater and freshwater to be allocated to agriculture in the year 2050 will be 909 and 395 mcm. This indicates that the main source of water for irrigation in agriculture in the country is treated wastewater. The challenge being faced is that the irrigation with treated wastewater can lead to leakage of pollution below the roots zone, such as nitrates that have been discovered in orchards with continuous irrigation with secondary treated wastewater at kibbutz Ramat Hakovesh and Mizrah, along with pesticide Atrazine discovered in the fields of kibbutz Maabarot.


Nasser A.,Institute of Soils | Mingelgrin U.,Institute of Soils
Chemosphere | Year: 2014

DCP (2,4-dichlorophenol) is the key-intermediate in the synthesis of some widely used pesticides and is an EPA priority pollutant. The mechanochemical breakdown of DCP loaded on birnessite (δ-MnO2), montmorillonite saturated with Na+ or Cu2+ and hematite was investigated. Mechanical force was applied by grinding of mixtures of DCP and the minerals, using mortar and pestle. Grinding of DCP for 5min with the montmorillonites or with hematite resulted in negligible degradation during grinding, while grinding with birnessite induced the immediate degradation of 90% of the loaded DCP. Incubation for 24h after grinding did result in up to 30% degradation of the DCP loaded on the other minerals tested.HPLC and LC-MS analysis revealed that the transformation of DCP yielded oligomerization products as well as partial dechlorination. DCP degradation on birnessite was accompanied with a substantial increase in the extractability of manganese from the mineral into an acidic aqueous solution, indicating that Mn(IV) in the mineral transformed into Mn(II) and that birnessite served as an electron acceptor in the transformation. The oligomerization and partial dechlorination brought about by grinding, suggest a reduction in bioavailability and toxicity. © 2013 Elsevier Ltd.


Zentner E.,Ben - Gurion University of the Negev | Weisbrod N.,Ben - Gurion University of the Negev | Gerstl Z.,Institute of Soils | Gasser G.,Hebrew University of Jerusalem | Ronen D.,Ben - Gurion University of the Negev
Chemosphere | Year: 2015

Spatial heterogeneity in the chemical concentration of interstitial water in the vadose zone was previously observed under apparently homogeneous surface conditions on two leveled fields sprinkler irrigated with treated sewage effluents on the phreatic Coastal Plain aquifer of Israel. This phenomenon greatly hampers the monitoring of groundwater quality. In this study we report on the presence of puddles of different size and shape that were sporadically observed in these fields. Temporal variability noted in the concentration of treated sewage effluents components in the puddles were considered to be related to evapotranspiration and degradation. For example: increases in the electrical conductivity (up to 1.32 mS/cm), and in the concentrations of chloride (up to 521 mg/L), dissolved organic carbon (up to 28.4 mg/L), and carbamazepine (up to 780 ng/L) and decreases in the concentrations of nitrate (up to 20.1 mg/L) and caffeine (3396 ng/L). Variable trends in concentration were observed for sulfamethoxazole, venlafaxine, 10-hydroxy-10,11-dihydrocarbamazepine and o-desmethylvenlafaxine. The presence of puddles was not necessarily related to areas with high irrigation water input. It is postulated that the continuous chemical variability in the puddles, whose location and size are also variable, determine a heterogeneous influx of solutes into the soil and subsequently into the vadose zone. © 2015 Elsevier Ltd.


PubMed | Institute of Soils
Type: | Journal: Chemosphere | Year: 2014

DCP (2,4-dichlorophenol) is the key-intermediate in the synthesis of some widely used pesticides and is an EPA priority pollutant. The mechanochemical breakdown of DCP loaded on birnessite (-MnO2), montmorillonite saturated with Na(+) or Cu(2+) and hematite was investigated. Mechanical force was applied by grinding of mixtures of DCP and the minerals, using mortar and pestle. Grinding of DCP for 5 min with the montmorillonites or with hematite resulted in negligible degradation during grinding, while grinding with birnessite induced the immediate degradation of 90% of the loaded DCP. Incubation for 24h after grinding did result in up to 30% degradation of the DCP loaded on the other minerals tested. HPLC and LC-MS analysis revealed that the transformation of DCP yielded oligomerization products as well as partial dechlorination. DCP degradation on birnessite was accompanied with a substantial increase in the extractability of manganese from the mineral into an acidic aqueous solution, indicating that Mn(IV) in the mineral transformed into Mn(II) and that birnessite served as an electron acceptor in the transformation. The oligomerization and partial dechlorination brought about by grinding, suggest a reduction in bioavailability and toxicity.

Loading Institute of Soils collaborators
Loading Institute of Soils collaborators