Plant nutrient management for enhanced productivity in intensive grain production systems of the United States and Asia

2002 ◽  
pp. 153-175 ◽  
Author(s):  
A. Dobermann ◽  
K. G. Cassman
Keyword(s):  
United States ◽  
Nutrient Management ◽  
Production Systems ◽  
The United States ◽  
Plant Nutrient ◽  
Grain Production

Developing twinning cattle for commercial production

2008 ◽  
Vol 48 (7) ◽  
pp. 930 ◽  
Author(s):  
L. J. Cummins ◽  
C. A. Morris ◽  
B. W. Kirkpatrick
Keyword(s):  
United States ◽  
Production Systems ◽  
The United States ◽  
Research Centre ◽  
Commercial Application ◽  
Term Selection ◽  
Calf Survival ◽  
Potential Benefits ◽  
Meat Animal

Long-term selection programs in the United States and New Zealand have developed twinning herds. In Nebraska, the United States Meat Animal Research Centre population had a calving rate of 1.56 per parturition in 2004. They have shown that the location of ovulation has an important effect on the success of pregnancy and that ovulations ≥3 are probably undesirable. These cattle have issues associated with calving difficulty and calf survival, which present challenges for commercial application. Intensive management using existing technology and/or future genetic improvement to address these traits are required to realise the potential benefits to beef production systems.

Hydrogeologic controls on the transport and fate of nitrate in ground water beneath riparian buffer zones: results from thirteen studies across the United States

2004 ◽  
Vol 49 (3) ◽  
pp. 47-53 ◽  
Author(s):  
L.J. Puckett
Keyword(s):  
United States ◽  
Organic Carbon ◽  
Ground Water ◽  
Nutrient Management ◽  
Riparian Zone ◽  
The United States ◽  
Riparian Buffer ◽  
Buffer Zones ◽  
Flow Paths ◽  
Riparian Buffer Zones

During the last two decades there has been growing interest in the capacity of riparian buffer zones to remove nitrate from ground waters moving through them. Riparian zone sediments often contain organic carbon, which favors formation of reducing conditions that can lead to removal of nitrate through denitrification. Over the past decade the National Water Quality Assessment (NAWQA) Program has investigated the transport and fate of nitrate in ground and surface waters in study areas across the United States. In these studies riparian zone efficiency in removing nitrate varied widely as a result of variations in hydrogeologic factors. These factors include (1) denitrification in the up-gradient aquifer due to the presence of organic carbon or other electron donors, (2) long residence times (>50 years) along ground-water flow paths allowing even slow reactions to completely remove nitrate, (3) dilution of nitrate enriched waters with older water having little nitrate, (4) bypassing of riparian zones due to extensive use of drains and ditches, and (5) movement of ground water along deep flow paths below reducing zones. By developing a better understanding of the hydrogeologic settings in which riparian buffer zones are likely to be inefficient we can develop improved nutrient management plans.

scholarly journals The risk for insufficient chill accumulation: a climate change perspective for apple and cherry production in the United States

2020 ◽  
Author(s):  
Hossein Noorazar ◽  
Lee Kalcsits ◽  
Vincent P. Jones ◽  
Matthew S. Jones ◽  
Kirti Rajagopalan
Keyword(s):  
United States ◽  
Potential Risk ◽  
Production Systems ◽  
Management Strategies ◽  
The United States ◽  
Fruit Production ◽  
Climate Projections ◽  
Spring Phenology ◽  
Tree Fruit ◽  
Production Risks

AbstractWinter chill accumulation is critical for the productivity and profitability of perennial tree fruit production systems. Several studies have quantified the impacts of global warming on risks of insufficient chill accumulation in the warmer tree fruit and nut production regions of the United States (US), such as the Southeast and California, where these risks are currently prevalent. In this work, we focus on the Pacific Northwest US – the largest production area in the US for apples, pears and cherries – and quantify the potential risk of insufficient chill accumulation. Our results highlight large spatial variations in response within the PNW, with northern areas projected to have reduced risks and southern areas projected to have increased risks. In the southern areas, rather than chill accumulation in and of itself, it is the combination of reduced and delayed chill accumulation with likely advancement in spring phenology that lead to production risks. In spite of future reductions to chill accumulation, risks of insufficient chill accumulation seem limited for apple even with advancement of spring phenology. Under the extreme “no climate policy” RCP 8.5 climate projections, the production risks are significant for early blooming crops (e.g. cherries) and varieties with relatively high chill portions requirements (e.g. Sam cherries), necessitating planning for management strategies such as frost protection and chemical management of budbreak to address potential risks which have not historically been a concern in the region. Under less extreme warming outcomes, the PNW tree fruit production systems are likely to remain resilient. Given that the convergence of the fulfillment of chilling requirements and environmental conditions promoting budbreak is where potential risk to perennial tree fruit production exists, future work should focus on understanding, modelling and projecting responses within this convergence space. Additionally, given significant spatial differences across a relatively small geographic range, it is also critical to understand and model these dynamics at a local landscape resolution for regions such as the PNW that faced limited risk historically, but could be exposed to new risks under a warming climate.

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