scholarly journals After the Storm: Fate and Leaching of Particulate Nitrogen (PN) in the Fluvial Network and the Influence of Watershed Sources and Moisture Conditions

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3182
Author(s):  
Chelsea Krieg ◽  
Erin Johnson ◽  
Erin Peck ◽  
Jinjun Kan ◽  
Shreeram Inamdar
Keyword(s):  
Global Climate ◽  
Moisture Regime ◽  
Particulate Nitrogen ◽  
Stream Bank ◽  
Drying And Rewetting ◽  
Moisture Regimes ◽  
C And N ◽  
Storm Deposits ◽  
Moisture Conditions ◽  
Fluvial Network

Large storms can erode, transport, and deposit substantial amounts of particulate nitrogen (PN) in the fluvial network. The fate of this input and its consequence for water quality is poorly understood. This study investigated the transformation and leaching of PN using a 56-day incubation experiment with five PN sources: forest floor humus, upland mineral A horizon, stream bank, storm deposits, and stream bed. Experiments were subjected to two moisture regimes: continuously moist and dry–wet cycles. Sediment and porewater samples were collected through the incubation and analyzed for N and C species, as well as the quantification of nitrifying and denitrifying genes (amoA, nirS, nirK). C- and N-rich watershed sources experienced decomposition, mineralization, and nitrification and released large amounts of dissolved N, but the amount of N released varied depending on the PN source and moisture regime. Drying and rewetting stimulated nitrification and suppressed denitrification in most PN sources. Storm deposits released large amounts of porewater N regardless of the moisture conditions, indicating that they could readily act as N sources under a variety of conditions. The inputs, processing, and leaching of large, storm-driven PN inputs become increasingly important as the frequency and intensity of large storms is predicted to increase with global climate change.

Soil moisture conditions affect the sensitivity ofBromus catharticusdormant seeds to light and the emergence pattern of seedlings

2009 ◽  
Vol 19 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Federico P.O. Mollard ◽  
Pedro Insausti
Keyword(s):  
Soil Moisture ◽  
Red Light ◽  
Soil Drought ◽  
Moisture Regime ◽  
Emergence Pattern ◽  
Light Pulses ◽  
Soil Moisture Regime ◽  
Moisture Regimes ◽  
Summer Temperatures ◽  
Moisture Conditions

AbstractThe soil moisture regime may affect dormancy of seeds and their sensitivity to signals that promote germination. We studied the effect of moisture regime on the sensitivity to light of dormantBromus catharticusseeds, and on the emergence pattern of seedlings. Seeds were incubated under continuously hydrated, continuously dehydrated, or fluctuating moisture regimes in a controlled environment (25°C, darkness) for 2 months. After moisture treatments, seeds were exposed to red or far-red light pulses, or to darkness, to determine germinability. In addition, grassland mesocosms with intact seed bank and vegetation were irrigated or subjected to a drought regime in a glasshouse at summer temperatures. After 2 months, the temperature was reduced to correspond to grassland temperatures in autumn; the canopy was removed and half of the mesocosms were covered with filters that exclude red light. Density ofB. catharticusseedlings was evaluated after 2 weeks. Dormancy decreased in continuously hydrated seeds but they still required red light for germination. In contrast, an important fraction of seeds that experienced continuously dehydrated or fluctuating moisture regimes germinated in darkness or after far-red light pulses. In the mesocosms that had experienced a soil drought, a higher density of seedlings emerged in the absence of red light than in the daily irrigated mesocosms. This indicates that a fraction ofB. catharticusseeds acquired the capability to germinate under the canopy, especially in the drought moisture regime. Results indicate that the soil moisture environment experienced during dormancy affects the sensitivity to light ofB. catharticusseeds, as well as the emergence pattern of seedlings.

Soybean (Glycine max) Response to AC 263,222 and Chlorimuron as Influenced by Soil Moisture

1995 ◽  
Vol 9 (3) ◽  
pp. 553-560 ◽  
Author(s):  
Larry J. Newsom ◽  
David R. Shaw
Keyword(s):  
Soil Moisture ◽  
Field Experiments ◽  
Sprinkler Irrigation ◽  
Moisture Stress ◽  
Yield Reduction ◽  
Moisture Regime ◽  
Natural Rainfall ◽  
Moisture Regimes ◽  
Ac 263,222 ◽  
Moisture Conditions

Field experiments conducted in 1992 and 1993 evaluated differential response of 20 soybean cultivars to POST application of AC 263,222 or chlorimuron, as influenced by soil moisture. Natural rainfall was supplemented with overhead sprinkler irrigation to achieve three moisture regimes: excessive (12.5 cm/wk), optimum (5 cm/wk), and low (non-irrigated). Chlorimuron and AC 263,222 injured soybean. Excessive moisture did not increase soybean injury with chlorimuron for any of the cultivars tested compared to optimum moisture; however, 17 of 20 cultivars were injured more by AC 263,222 in combination with excessive moisture than optimum moisture. AC 263,222 reduced the height of five cultivars. Photosynthetic rate of several cultivars was reduced by both AC 263,222 and chlorimuron. Neither herbicide affected the number of nodes per main stem or seed weight; however, pod numbers were reduced for several cultivars with both herbicides. In the low moisture regime, AC 263,222 delayed the maturity of 18 of 20 cultivars with ‘Hutcheson’ maturity delayed 7.1 d. Excessive moisture when combined with AC 263,222 reduced yields for 12 cultivars, compared to five cultivars with chlorimuron. Under optimum moisture conditions, AC 263,222 reduced the yield of 10 cultivars, whereas chlorimuron reduced the yield of 9 cultivars. Low moisture stress only resulted in a yield reduction with 3 cultivars treated with AC 263,222.

Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings

2021 ◽  
Author(s):  
Xiao Wang ◽  
Xiaoli Wei ◽  
Gaoyin Wu ◽  
Shengqun Chen
Keyword(s):  
Carbon Dioxide ◽  
Enzyme Activities ◽  
Atmospheric Carbon Dioxide ◽  
Global Climate ◽  
Co2 Concentration ◽  
Rubisco Activase ◽  
Plant Responses ◽  
N Metabolism ◽  
C And N ◽  
Phoebe Bournei

Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

scholarly journals Soil moisture depletion and ground water use by bed planted barley as influenced by cultivars, crop geometry and moisture regimes

2017 ◽  
Vol 9 (3) ◽  
pp. 1465-1468 ◽  
Author(s):  
Naveen Kumar ◽  
Suresh Kumar ◽  
Parveen Kumar ◽  
Meena Sewhag
Keyword(s):  
Soil Moisture ◽  
Field Experiment ◽  
Ground Water ◽  
Water Use ◽  
Moisture Regime ◽  
Rabi Season ◽  
Shallow Water Table ◽  
Moisture Regimes ◽  
Crop Geometry ◽  
Plot Design

A field experiment was conducted during rabi season 2011-2012 at Research Farm, CCS Haryana Agri-cultural University, Hisar, Haryana (India) to study the periodic soil moisture depletion and ground water use by bed planted barley as influenced by cultivars, crop geometry and moisture regimes under shallow water table conditions. The experiment was laid out in split plot design with three replications keeping combinations of three cultivars viz., BH 393, BH 902 and BH 885 and two crop geometries viz 2 rows per bed and 3 rows per bed (70 cm wide with 40 cm top and 30 cm furrow) in main plots and three moisture regimes (irrigation at IW/CPE 0.3, 0.4 & 0.5) in sub plots. The results revealed that maximum soil moisture depletion (105 mm) and ground water contribution (62 mm) were recorded in BH 902, followed by BH 393 and BH 885. Among crop geometries, soil moisture depletion (96.6 mm) and ground water contribution (61 mm) were recorded higher in 3 rows per bed than 2 rows per bed. Among three moisture regimes, the soil moisture depletion (108 mm) and ground water contribution (65 mm) decreased with increase in moisture regime from irrigation at IW/CPE 0.3 to irrigation at IW/CPE 0.4 or 0.5.

Monitoring Agricultural Drought in the Near East

2005 ◽  
Author(s):  
Eddy De Pauw
Keyword(s):  
Near East ◽  
Potential Evapotranspiration ◽  
Groundwater Resources ◽  
Winter Season ◽  
Aridity Index ◽  
Agricultural Drought ◽  
Moisture Regime ◽  
Temperature Regimes ◽  
Moisture Regimes ◽  
Dry Climates

The countries of North Africa and West Asia, hereafter referred to as the “Near East,” cover a large part of the world (more than 7,200,000 km2). This region is characterized by diverse but generally dry climates, in which evaporation exceeds precipitation. The level of aridity is indicated by the aridity index, the ratio of annual precipitation to annual potential evapotranspiration, calculated by the Penman method (UNESCO, 1979). The degree of aridity is shown spatially in figure 16.1 and summarized per country in table 16.1. These data show that the region is characterized by humid, subhumid, semiarid, and arid to hyperarid moisture regimes. In addition, temperature regimes vary considerably, particularly due to the differences in altitudes and, to a lesser extent, due to the oceanic/continental influences. For most of the region, the precipitation generally occurs during the October–April period and thus is concentrated over the winter season. Table 16.1 shows that, with more than 90% of the land area in hyperarid, arid, or semiarid moisture regimes, aridity is very significant in the Near East. Turkey is better endowed with surface and groundwater resources due to the orographic capture of Atlantic cyclonal precipitation, but much of the interior is semiarid. If one excludes the hyperarid zones, which cover the driest deserts and have no potential for agricultural use, nearly 34% of the region, or about 2,460,000 km2, is dryland (i.e., the area with arid or semiarid moisture regime). These are the areas with some potential for either dryland farming (in semiarid zones) or for extensive rangeland (in arid zones). In the Near East countries, agriculture contributes about 10–20% to the gross domestic product and is therefore a major pillar of their economies. However, the indirect importance of agriculture is larger because it provides the primary goods that constitute the majority of merchandise exports and because of the relatively high number of people employed in agriculture. Because of the high degree of aridity in large parts of the region, agriculture in the Near East is particularly vulnerable to drought. Most of the agricultural systems depend on rainfall.

scholarly journals Soil moisture regimes in Mexico in a global 1.5°C warming scenario

2019 ◽  
Vol 11 (4) ◽  
pp. 465-482 ◽  
Author(s):  
Jesus David Gomez Diaz ◽  
Alejandro I. Monterroso ◽  
Patricia Ruiz ◽  
Lizeth M. Lechuga ◽  
Ana Cecilia Conde Álvarez ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Regional Scale ◽  
Moisture Regime ◽  
Monthly Precipitation ◽  
Climate Change Scenarios ◽  
Content Type ◽  
Warming Scenario ◽  
Moisture Regimes ◽  
Gfdl Model

Purpose This study aims to present the climate change effect on soil moisture regimes in Mexico in a global 1.5°C warming scenario. Design/methodology/approach The soil moisture regimes were determined using the Newhall simulation model with the database of mean monthly precipitation and temperature at a scale of 1: 250,000 for the current scenario and with the climate change scenarios associated with a mean global temperature increase of 1.5°C, considering two Representative Concentration Pathways, 4.5 and 8.5 W/m2 and three general models of atmospheric circulation, namely, GFDL, HADGEM and MPI. The different vegetation types of the country were related to the soil moisture regimes for current conditions and for climate change. Findings According to the HADGEM and MPI models, almost the entire country is predicted to undergo a considerable increase in soil moisture deficit, and part of the areas of each moisture regime will shift to the next drier regime. The GFDL model also predicts this trend but at smaller proportions. Originality/value The changes in soil moisture at the regional scale that reveal the impacts of climate change and indicate where these changes will occur are important elements of the knowledge concerning the vulnerability of soils to climate change. New cartography is available in Mexico.

Soybean (Glycine max) Response to Chlorimuron and Imazaquin as Influenced by Soil Moisture

1992 ◽  
Vol 6 (2) ◽  
pp. 389-395 ◽  
Author(s):  
Larry J. Newsom ◽  
David R. Shaw
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Plant Height ◽  
Field Experiments ◽  
Soybean Cultivar ◽  
Moisture Regime ◽  
Natural Rainfall ◽  
Herbicide Treatment ◽  
Reduced Height ◽  
Moisture Regimes

Field experiments were conducted in 1989 and 1990 to evaluate differential soybean cultivar tolerance to chlorimuron and imazaquin applied PPI, as influenced by soil moisture. Natural rainfall was supplemented with irrigation to achieve three moisture regimes: low (nonirrigated), optimum (5 cm wk–1), and excessive (15 cm wk–1). Imazaquin at 140 g ai ha–1did not adversely affect height or yield of cultivars under any of the moisture regimes. Excessive moisture, regardless of herbicide treatment, reduced height and yield with many of the cultivars. Chlorimuron at 80 g ai ha–1caused additional plant height reductions of 8 cm or more with ‘Asgrow 5403% ‘Asgrow 5979’, ‘Coker 686’, ‘Asgrow 6785’, ‘Hartz 6686’, and 'Sharkey’ in the excessive moisture regime, and yield was reduced 450 kg ha–1or more with ‘Hutcheson’, ‘Terra-Vig 515’, Coker 686, Asgrow 6785, and Hartz 6686. Chlorimuron in the optimum moisture regime reduced the height of Coker 686 and ‘Deltapine 566’ 10 and 11 cm, respectively; however, no yield reductions were noted.

EFFECTS OF NITROGEN, TEMPERATURE, AND MOISTURE REGIME ON THE YIELD AND PROTEIN CONTENT OF NEEPAWA WHEAT

1972 ◽  
Vol 52 (2) ◽  
pp. 179-185 ◽  
Author(s):  
J. R. D. PARTRIDGE ◽  
C. F. SHAYKEWICH
Keyword(s):  
Grain Yield ◽  
Moisture Regime ◽  
Fertilizer N ◽  
Moisture Regimes ◽  
Initial Decrease ◽  
Percent Protein ◽  
Influence Of Temperature On ◽  
Subsequent Rise ◽  
Significant Direct Effect ◽  
Moderate Stress

Experiments were conducted in growth chambers growing wheat on a soil initially low in NO3-N. At rates up to 100 ppm N, grain yield increased with succeeding increments of fertilizer-N. Increased temperatures (15, 21, and 25 C) significantly decreased grain yield in most instances. Low to moderate stress soil moisture regimes (0.3–0.5 and 0.3–2.8 bars) had no significant influence on grain yield. A line was plotted for percent protein vs. added fertilizer-N resulting in a concave protein curve, with an initial decrease in protein to 50 ppm N and a subsequent rise with 100 and 200 ppm N. At each level of N, a close negative correlation was shown between percent protein and grain yield. The effect of increased temperature in increasing percent protein was found to be mostly an indirect effect through the influence of temperature on grain yield. Moisture regime was found to have no significant direct effect on percent protein.

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