Are catchment-scale nitrogen and phosphorous use efficiencies controlled by climate?

2021 ◽  
Author(s):  
Anna Scaini ◽  
Stefano Manzoni
Keyword(s):  
Nutrient Retention ◽  
Nutrient Leaching ◽  
Nutrient Loss ◽  
Agricultural Area ◽  
Agricultural Fields ◽  
Negative Consequences ◽  
Mixed Effect ◽  
Nutrient Use ◽  
Hydrologic Conditions ◽  
Nutrient Use Efficiencies

<p>Nutrient loss from agricultural fields imparts increased fertilizer costs as well as negative consequences for the natural environment. Given that water availability mediates both nutrient uptake by plants as well as nutrient leaching, we hypothesize that hydrologic conditions can explain variations in nutrient use efficiencies, defined as ratios of the nutrient amounts in harvested yield and in inputs. We analyze data from 110 US catchments with agricultural area comprising more than 10% of the watershed and compute nitrogen and phosphorus use efficiencies (NUE and PUE) over the period 1988-2007. To assess if NUE and PUE are related to hydrologic conditions, we consider the evaporative ratio ET/P (calculated as evapotranspiration divided by precipitation) as a predictor in a linear mixed effect model. We test the hypotheses that the nutrient use efficiencies increase with ET/P, through increased water and nutrient retention, and that the nutrient efficiencies increase through time. We found that both nutrient use efficiencies increased through time: NUE increased in the period analyzed in 88% of catchments, while PUE in 90% of catchments. Both NUE and PUE were largely driven by significant increases in N and P amounts in yield. The evaporative ratio was positively related to NUE. Moreover, we found an interaction between ET/P and time, such that the ET/P effect on NUE decreased in the period 1998–2007. The evaporative ratio was also positively related to PUE. Other potential drivers were assessed, including interaction between ET/P and time, as well as the percentage of agricultural area in each catchment. Our results show that changes in climate that include increased evaporation and decreased precipitation can lead to increase N use efficiencies without decreasing yields. The implications of our findings in terms of the release of N and P to water bodies has particular relevance in terms of climate change, as higher temperatures and lower precipitation (i.e. increasing evaporative ratios) will potentially lead to increased nutrient retention and therefore decreased nutrient leaching from agricultural fields.</p>

Nutrient-Use Patterns in Nursery Crops

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557a-557
Author(s):  
Mary Ann Rose ◽  
Barbara Biernacka
Keyword(s):  
Nutrient Retention ◽  
The United States ◽  
Soil Conditions ◽  
Woody Ornamentals ◽  
Use Patterns ◽  
Nutrient Demand ◽  
Nutrient Use ◽  
Fertilizer Recommendations ◽  
Retention Characteristics ◽  
Practical Constraints

Long-standing fertilizer recommendations for field-grown nursery and landscape ornamentals are based on maximizing growth, not nutrient efficiency. Further, these recommendations fall short because of failure to consider 1) the extent of crop nutrient removal, 2) varying nutrient retention characteristics of soils across the United States, and 3) a body of research that suggests that woody ornamentals have a limited response to fertilization under most soil conditions. Concern for the environmental impact of fertilization justifies a reevaluation of current nursery fertilization practices, as well a discussion of the practical constraints on the adoption of new approaches, e.g., nutrient demand-driven fertilization. Research on the nutrient use patterns of woody plants will be reviewed with emphasis on implications for increasing fertilization efficiency. OSU research on water availability and nutrient-use interactions also will be presented.

scholarly journals Modeling Past, Present, and Future Urban Growth Impacts on Primary Agricultural Land in Greater Irbid Municipality, Jordan Using SLEUTH (1972–2050)

2021 ◽  
Vol 10 (4) ◽  
pp. 212
Author(s):  
Rana N. Jawarneh
Keyword(s):  
Land Use ◽  
Growth Model ◽  
Urban Growth ◽  
Agricultural Land ◽  
Urban Land Use ◽  
Agricultural Area ◽  
Grand Challenge ◽  
Negative Consequences ◽  
Urban Growth Model ◽  
Rate Of Increase

Urban expansion and loss of primarily agricultural land are two of the challenges facing Jordan. Located in the most productive agricultural area of Jordan, Greater Irbid Municipality (GIM) uncontrolled urban growth has posed a grand challenge in both sustaining its prime croplands and developing comprehensive planning strategies. This study investigated the loss of agricultural land for urban growth in GIM from 1972–2050 and denoted the negative consequences of the amalgamation process of 2001 on farmland loss. The aim is to unfold and track historical land use/cover changes and forecast these changes to the future using a modified SLEUTH-3r urban growth model. The accuracy of prediction results was assessed in three different sites between 2015 and 2020. In 43 years the built-up area increased from 29.2 km2 in 1972 to 71 km2 in 2015. By 2050, the built-up urban area would increase to 107 km2. The overall rate of increase, however, showed a decline across the study period, with the periods of 1990–2000 and 2000–2015 having the highest rate of built-up areas expansion at 68.6 and 41.4%, respectively. While the agricultural area increased from 178 km2 in 1972 to 207 km2 in 2000, it decreased to 195 km2 in 2015 and would continue to decrease to 188 km2 by 2050. The district-level analysis shows that from 2000–2015, the majority of districts exhibited an urban increase at twice the rate of 1990–2000. The results of the net change analysis of agriculture show that between 1990 and 2000, 9 districts exhibited a positive gain in agricultural land while the rest of the districts showed a negative loss of agricultural land. From 2000 to 2015, the four districts of Naser, Nozha, Rawdah, and Hashmyah completely lost their agricultural areas for urbanization. By 2050, Idoon and Boshra districts will likely lose more than half of their high-quality agricultural land. This study seeks to utilize a spatially explicit urban growth model to support sustainable planning policies for urban land use through forecasting. The implications from this study confirm the worldwide urbanization impacts on losing the most productive agricultural land in the outskirts and consequences on food production and food security. The study calls for urgent actions to adopt a compact growth policy with no new land added for development as what is available now exceeds what is needed by 2050 to accommodate urban growth in GIM.

In vitro rumen degradability, ammonia levels and pH of different spices

2009 ◽  
Vol 2009 ◽  
pp. 193-193
Author(s):  
M M H Khan ◽  
A S Chaudhry ◽  
H Lima Neto ◽  
M R Virk
Keyword(s):  
Developing Countries ◽  
Dry Matter ◽  
Ammonia Level ◽  
Rumen Fermentation ◽  
Nutrient Loss ◽  
Nutrient Contents ◽  
Nutrient Use ◽  
Alternative Sources

In developing countries, low quality forages (LQF), like cereal straws are the main basal feed for ruminants. But these forages are low in nutrient contents and so the ruminants cannot utilize these forages effectively which results in poor ruminant health and production. So it is needed to improve the quality of these forages. Conversely, rumen fermentation of these forages may result in considerable energy and protein losses as methane and ammonia N which cause pollution to the environment. So it is needed to find out additives that can also be used as supplements to reduce nutrient loss as methane and nitrogen. It would be desirable if these supplements or additives improve the efficiency of nutrient use in the rumen as well. Herbs and spices can be used as alternative sources. Researchers have been using plant extracts to manipulate rumen fermentation. But processing extracts from plant products will be costly and will require expensive instruments. Khan and Chaudhry (2008) have reported the potential in using spices to modify degradability and fermentation of different forages. However, it may be helpful to observe the degradability and fermentation profiles of these spices alone before their use as additives to improve forage degradability perhaps by stimulating the fibrolytic and or inhibiting the undesirable microbes. Therefore, this study compared the in vitro dry matter degradability (IVD) and rumen ammonia level (AL) and pH of different concentrations of selected spices at different times.

Fertiliser use efficiency by containerised nursery plants. 3. Effect of heavy leaching and damaged fertiliser prills on plant growth, nutrient uptake, and nutrient loss

1999 ◽  
Vol 50 (2) ◽  
pp. 217 ◽  
Author(s):  
D. O. Huett ◽  
S. C. Morris
Keyword(s):  
Plant Growth ◽  
Nutrient Uptake ◽  
Shoot Growth ◽  
Ground Cover ◽  
Nutrient Content ◽  
Nutrient Leaching ◽  
Nutrient Loss ◽  
Nutrient Concentrations ◽  
Leaching Loss ◽  
Nutrient Amendment

Nutrient leaching loss, plant growth, and nutrient uptake of 4-week (transplanting to sale) ground-cover species were investigated under a range of leaching conditions and with different sources of a controlled- release fertiliser (CRF), Osmocote NPK (3–4 month) (Osm). Osm was applied pre-planting at a rate equivalent to 800 g N/m3 to pots containing sand, and composted pinebark and hardwood sawdust medium that had received nutrient amendment during formulation. Two experiments were conducted in a glasshouse over summer–autumn where irrigation treatments produced defined leachate volumes. In Expt 1, leachate volumes of <5, 50, and 200 mL every 2 days each received an additional single heavy leaching event of 400 mL after 1, 2, or 3 weeks. In Expt 2, the 3 leachate volumes were each fertilised with new Osm (a newly purchased Osm) or old Osm (a 2-year-old source), where both of these sources contained 0.5–1.5% visibly damaged prills; and damaged Osm, where damaged prills were used exclusively. In both experiments, increasing leachate volume increased (P < 0.001) leaching of N (nitrate + ammonium), P, K, Ca, and Mg. In Expt 1, leaching was highest (P < 0.01) when the heavy leaching event occurred after 2 or 3 weeks for N and after 2 weeks for P. When damaged Osm was used, N, P, and K loss was 3–15 times higher (P < 0.001) than from new and old Osm (98.5–99.5% undamaged). The highest leaching loss of N, P, K, Ca, and Mg occurred in the first week after potting up, with damaged prills at highest leaching volume. Increasing leachate volume (in the presence of a heavy leaching event) reduced (P < 0.001) electrical conductivity (EC) of potting medium after 4 weeks from 1.02 to 0.54 dS/m. Damaged prills reduced (P < 0.001) EC at the high leachate volume in relation to new Osm (2.38 v. 0.29 dS/m). Treatments that increased (P < 0.05) nutrient leaching generally reduced (P < 0.05) nutrient concentrations in shoots and depressed the growth of some plant species. Shoot growth of 2 of 5 species was reduced (P < 0.001) at the highest leachate volume with an additional heavy leaching event in Week 1 or 2, and root growth of all but the slowest growing species declined with increasing leachate volume. Damaged prills reduced (P < 0.001) shoot growth of 2 of the 5 ground-cover species. This study demonstrated that excessive leaching and the use of damaged prills for containerised nursery plants fertilised with CRF results in high nutrient loss, low residual nutrient content, reduced nutrient uptake in shoots, and reduced shoot growth of some species.

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