Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Soil Science Society of America journal 63 (1999), S. 1237-1243 
    ISSN: 1435-0661
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Medicago sativa L.) usually obtains a high percentage of its required N via symbiotic N fixation, additional fertilizer N applied once in the spring can increase forage yields. However, little is known about alfalfa yield response to low N rates (〈50 kg N ha−1) immediately following each cutting. Low N rates (immediately following each cutting) were evaluated for total alfalfa dry matter production on a Grant silt loam (fine-silty, mixed, thermic, Udic Argiustoll). This nonirrigated experiment was initiated on a 2-yr-old alfalfa stand where sufficient P and K had been applied. Nitrogen rates of 11, 22, and 44 kg N ha−1 were applied immediately following each cutting for 5 yr (4–5 cuttings yr−1). After 5 yr of continuous N application, no differences in soil NH4–N or NO3–N were found at depths 〉15 cm (0- to 240-cm sampling depth). In 1994, total alfalfa dry matter yield (sum of five harvests) increased 1.29 Mg ha−1 from a total annual N application of 110 kg N ha−1 (22 kg N ha−1 following each cutting). Total forage N decreased from the second to the fifth harvest in most years. By-harvest dry matter yield increases due to applied N were only found in late-season harvests, consistent with late-season decreased N2-fixing capacity in alfalfa documented by others.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Soil Science Society of America journal 63 (1999), S. 1724-1733 
    ISSN: 1435-0661
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Cynodon dactylon L.) sod at two locations. Eight soil cores (0–15 cm deep) were collected and composited from each 0.3- by 0.3-m plot. Semivariance analysis was used to estimate the range over which samples of the five soil variables (total N, extractable P, and K, organic C, and pH) and two plant variables (forage total N and biomass) were related. Semivariance statistics including the nugget, sill, correlation range, and integral scale were calculated. Correlation ranges were between 1.9 and 11.4 m with corresponding integral scales between 0.5 and 2.1 m. At one location, P exhibited nested sills with multiple ranges. Results indicate that the fundamental field-element dimensions (the area over which variable rate fertilizer applicators should sense and apply materials) is likely to be 1.0 by 1.0 m or smaller. To describe the variability encountered in these experiments, soil and plant measurements should be made at the meter or submeter level.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1435-0661
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: 2 ). A 2.13 by 21.33 m area was selected for intensive forage and soil sampling from two bermudagrass [Cynodon dactylon (L.) Pers.] pasture sites (Burneyville and Efaw, OK). Each 2.13 by 21.33 m area was partitioned into 490, 0.30 by 0.30 m (1 by 1 ft) subplots. Bermudagrass forage was hand harvested at ground level from each 0.30 by 0.30 m subplot. Prior to forage harvest, spectral radiance readings (red, 671±6 nm; green, 550 ±6 nm; and near infrared, 780±6 nm) were recorded from each subplot. Composite samples composed of eight soil cores, 0 to 15 cm deep and 1.9 cm in diameter, were collected from each subplot. At both locations, bermudagrass forage yield harvested from 0.30 by 0.30 m subplots ranged from ,1300 to .10 000 kg ha-1. Soil pH ranged from 4.37 to 6.29 within the 2.12 by 21.33 m area at Burneyville and 5.37 to 6.34 at Efaw. No P or K fertilizer would have been recommended at Efaw using mean soil test P and K. The range in recommended fertilizer rates would have been 0 to 31 and 0 to 17 kg P ha-1 and 0 to 107 and 0 to 108 kg K ha-1 at Burneyville and Efaw, respectively, if recommendations were based on individual 0.30 by 0.30 m grid data. Significant differences in surface soil test analyses were found when samples were 〈1 m apart for both mobile and immobile nutrients.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...