production area. The goal of efficient irrigation is to supply enough water for profitable production but not so much that unnecessary leaching occurs. One method for monitoring irrigation efficiency under a wide range of production conditions is to monitor
Jeff B. Million and Thomas H. Yeager
S.M. Scheiber, R.C. Beeson Jr, J. Chen, Q. Wang, and B. Pearson
Contamination of groundwater supplies with nitrates from agricultural endeavors has been a concern for decades. Booming residential and commercial development has turned attention to nitrate leaching from commercial and residential lawns
Michael W. Olszewski, Samara J. Danan, and Thomas J. Boerth
rate), or 0.012 mL·L −1 APG/BLK. After drainage, leaching fraction (LF) was calculated as the percentage volume of leachate divided by 300 mL applied. Visible wetting of substrate was evaluated by wettability rating (WR; Fig. 1 ). Irrigated substrates
Raul I. Cabrera, Richard Y. Evans, and J. L. Paul
Nitrogen leaching losses of 21, 40 and 49% were measured from container-grown `Royalty' roses irrigated for one year with nutrient solutions containing 77, 154 and 231 mg N/l. There were no significant differences in number of flowers per plant or dry matter per plant. The N present in the harvested flowers accounted for 43, 27 and 17% of the N applied for the 77, 154 and 231 mg N/l treatments, respectively.
Plants receiving 154 mg N/l at leaching fractions of 0.1, 0.25 and 0.5 had corresponding N leaching losses of 22, 38 and 56%. In this experiment, however, the 0.5 leaching fraction produced yields significantly higher than those of the 0.1 and 0.25 treatments. The N recovered in the harvested flowers accounted for 28, 25 and 19% of that applied to the 0.1, 0.25 and 0.5 treatments, respectively.
The results of these studies suggest that modifications in current irrigation and fertilization practices of greenhouse roses would result in a considerable reduction of N leaching losses and enhance N fertilizer use efficiency, without loss of cut flower yield and quality.
Mark V. Yelanich and John A. Biernbaum
The influence of fertilizer concentration and leaching volume on the quantity of applied N and water that were leached from a container-grown poinsettia crop (Euphorbia pulcherrima Willd.) was investigated. The NO3-N quantity leached after 71 days increased with higher NO3-N application rates (7, 14, or 28 mol NO3-N/m3) and higher leaching volumes; it ranged from 0.03 g NO3-N [7 mol·m-3, 0.00 container capacity leached (CCL)] to 7.65 g NO3-N (28 mol·m-3, 1.0 CCL). The NO3-N concentration for saturated media extracts increased with lower leaching volumes and higher fertilizer concentrations. For example, when 7 mol NO3-N/m3 was applied, NO3-N in the medium was 27.1 mol NO3-N/m3 when 0 CCL was used, but it was 8.6 mol NO3-N/m3 when 1.0 CCL was used. Shoot height and dry mass were not affected by the treatments. Leaching treatments also did not influenced leaf area, but leaf area was larger at 7 compared to 14 or 28 mol NO3-N/m3.
Kathryn M. Santos, Paul R. Fisher, and William R. Argo
reduce rooting percentage ( Geneve et al., 2004 ). Improved irrigation management may help reduce nutrient, pesticide, and trace element loads in irrigation runoff to surface waters as well as leaching of agricultural chemicals into groundwater supplies
Amy L. Shober, Andrew K. Koeser, Drew C. McLean, Gitta Hasing, and Kimberly K. Moore
previously published work to determine the impacts of application rate, method, and timing on woody ornamental health and N leaching from urban residential planting beds. The overall goal of this study was to refine current fertilization standards and BMPs
Jeff B. Million and Thomas H. Yeager
places great demand on water managers to apply water efficiently at each application to avoid excessive leaching. This is particularly true for microirrigated, spray-stake production in which the water application rates (e.g., 15–40 cm·h −1 ) are
Catherine S. M. Ku and David R. Hershey
Single-pinched `Yours Truly' geranium (Pelargonium × hortorum) were greenhouse grown in 15-cm diameter pots. They received constant liquid fertigation with a modified Hoagland solution #1 at 0.25, 0.5, 1.0, and 1.5 strength. The 1.0 strength Hoagland solution contained 210 mg/L NO3-N and 31 mg/L P. Leaching fractions (LFs) were 0, 0.2 and 0.4. The total P applied via fertigation ranged from 33 mg at 0 LF and 0.25x Hoagland to 407 mg at 0.4 LF and 1.5x Hoagland. The leachate P concentration ranged from <5 mg/L to -60 mg/L. The P concentration in the recently matured leaves was in the acceptable range for all treatments. We were able to recover 90 to 99% of the applied P by analyzing the shoots, soilless medium, and leachate. Only 4% of the recovered P was in the leachate for plants receiving 0.5x Hoagland and a 0.2 LF. However, these plants were equal in yield to plants receiving higher fertigation rates and higher LFs.
Clyde W. Fraisse, Zhengjun Hu, and Eric H. Simonne
production (as a response to a low probability of leaching rainfall occurrence) and, conversely, if a high probability in leaching rain occurrence would justify an increase in fertilization recommendation. Ultimately, as illustrated in the wheat and canola