Soil heterogeneity and potato fertilizer recommendations

1971 ◽  
Vol 48 (5) ◽  
pp. 163-173 ◽  
Author(s):  
R. Kunkel ◽  
C. D. Moodie ◽  
T. S. Russell ◽  
N. Holstad
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557a-557
Author(s):  
Mary Ann Rose ◽  
Barbara Biernacka

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.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Jorge Lopez-Jimenez ◽  
Nicanor Quijano ◽  
Alain Vande Wouwer

Climate change and the efficient use of freshwater for irrigation pose a challenge for sustainable agriculture. Traditionally, the prediction of agricultural production is carried out through crop-growth models and historical records of the climatic variables. However, one of the main flaws of these models is that they do not consider the variability of the soil throughout the cultivation area. In addition, with the availability of new information sources (i.e., aerial or satellite images) and low-cost meteorological stations, it is convenient that the models incorporate prediction capabilities to enhance the representation of production scenarios. In this work, an agent-based model (ABM) that considers the soil heterogeneity and water exchanges is proposed. Soil heterogeneity is associated to the combination of individual behaviours of uniform portions of land (agents), while water fluxes are related to the topography. Each agent is characterized by an individual dynamic model, which describes the local crop growth. Moreover, this model considers positive and negative effects of water level, i.e., drought and waterlogging, on the biomass production. The development of the global ABM is oriented to the future use of control strategies and optimal irrigation policies. The model is built bottom-up starting with the definition of agents, and the Python environment Mesa is chosen for the implementation. The validation is carried out using three topographic scenarios in Colombia. Results of potential production cases are discussed, and some practical recommendations on the implementation are presented.


Oikos ◽  
2021 ◽  
Author(s):  
Yongjie Liu ◽  
Michiel F. Bortier ◽  
Ivan Nijs ◽  
Yongshuo Fu ◽  
Zhenqing Li ◽  
...  

2021 ◽  
Author(s):  
Jason Smith ◽  
Richard A Hallett ◽  
Maha Deeb ◽  
Peter M Groffman

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joseph R. Roscioli ◽  
Laura K. Meredith ◽  
Joanne H. Shorter ◽  
Juliana Gil-Loaiza ◽  
Till H. M. Volkmann

AbstractSoil microbes vigorously produce and consume gases that reflect active soil biogeochemical processes. Soil gas measurements are therefore a powerful tool to monitor microbial activity. Yet, the majority of soil gases lack non-disruptive subsurface measurement methods at spatiotemporal scales relevant to microbial processes and soil structure. To address this need, we developed a soil gas sampling system that uses novel diffusive soil probes and sample transfer approaches for high-resolution sampling from discrete subsurface regions. Probe sampling requires transferring soil gas samples to above-ground gas analyzers where concentrations and isotopologues are measured. Obtaining representative soil gas samples has historically required balancing disruption to soil gas composition with measurement frequency and analyzer volume demand. These considerations have limited attempts to quantify trace gas spatial concentration gradients and heterogeneity at scales relevant to the soil microbiome. Here, we describe our new flexible diffusive probe sampling system integrated with a modified, reduced volume trace gas analyzer and demonstrate its application for subsurface monitoring of biogeochemical cycling of nitrous oxide (N2O) and its site-specific isotopologues, methane, carbon dioxide, and nitric oxide in controlled soil columns. The sampling system observed reproducible responses of soil gas concentrations to manipulations of soil nutrients and redox state, providing a new window into the microbial response to these key environmental forcings. Using site-specific N2O isotopologues as indicators of microbial processes, we constrain the dynamics of in situ microbial activity. Unlocking trace gas messengers of microbial activity will complement -omics approaches, challenge subsurface models, and improve understanding of soil heterogeneity to disentangle interactive processes in the subsurface biome.


Weed Science ◽  
2001 ◽  
Vol 49 (6) ◽  
pp. 798-805 ◽  
Author(s):  
Martin M. Williams II ◽  
David A. Mortensen ◽  
Alex R. Martin ◽  
David B. Marx

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