The Growth of Certain Conifers as Influenced by Different Fertilizer Treatments<sup>1</sup>

McIntyre, Arthur C.

doi:10.2134/agronj1930.00021962002200060012x

Cited by 3 publications

(2 citation statements)

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“…He mentioned that a liquid solution of AS could be applied over the top of pine seedlings if growth was below expectations. Others also reported good results from AS fertilization (McIntyre and White 1930;Rosendahl and Korstian 1945).…”

Section: Historymentioning

confidence: 92%

Use of sulphur in bareroot pine and hardwood nurseries

South

2023

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During the 20th century, managers at sandy nurseries utilized sulphur (S) to lower soil pH and mitigate the risk of iron deficiency. During that time, however, applying S as a fertilizer was a rare event. At many nurseries, S in rain and irrigation water was sufficient to avoid visual deficiency symptoms. The S status of soil and foliage was typically unknown, and many researchers did not test for S due to the additional cost. Consequently, S became the most neglected macronutrient. While a few nursery trials demonstrated that elemental S reduced damping-off and increased height growth, a majority showed no benefit after applying S at rates lower than 100 kg ha-1. Even so, by 1980, S-deficiencies occurred at bareroot nurseries in Alabama, Oklahoma, Virginia, Wisconsin, the United Kingdom, and likely in North Dakota and New York. The risk of a deficiency increases when N-only fertilizers are applied to seedbeds. Due to research, experience and the precautionary principle, several managers transitioned to using ammonium sulfate instead of, less expensive, N-only nitrogen fertilizers. After soil tests became affordable, managers began to ask questions about the need to apply S to seedbeds. Only a few hydroponic trials with small pine seedlings have been used to estimate “threshold” or “critical values” for foliar S. Since an initial 1,500 μg g-1 S value is “unreliable” for pine seedlings, some authors lowered the value to 1,100 μg g-1 and even as low as 500 μg g-1 S. Others ignore all estimates based on total S concentrations and, instead, monitor only foliar SO4 levels.

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Section: Historymentioning

confidence: 92%

Use of sulphur in bareroot pine and hardwood nurseries

South

2023

REFOR

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“…Table 8. The effect of CaCO3 fertilization on heights (mm) and mass (g) of pines grown outside in soil (McIntyre and White 1930;Wahlenberg 1930;Lunt 1947) or in greenhouses. Recommended soil acidity for pine seedbeds is pH 4.5 to 5.5. pH = before treatment.…”

Section: Caco3mentioning

confidence: 99%

Use of calcium in bareroot pine nurseries

South

2022

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Bareroot nursery managers may apply dolomite, gypsum, or Ca-nitrate to increase Ca in nursery soils. Although a few managers follow S.A. Wilde’s recommendations and maintain soil at levels of 500 to 1,000 μg g-1 Ca, there is no need to keep Ca levels this high. In contrast, managers at sandy nurseries apply Ca when soil tests drop below 200 μg g-1 Ca. In fact, acceptable pine seedlings have been produced in irrigated soil with <100 μg g-1 available Ca. In plantations, asymptomatic wildlings grow when topsoil contains 17 μg g-1 Ca. In sandy soils, applying too much gypsum can result in a temporary Mg deficiency and too much lime will result in chlorotic needles. Managers apply Ca when foliar levels fall below a published “critical value.” The belief that the critical value for Ca varies by stock type is not valid. In fact, numerous “critical” values are invalid since they were not determined using growth response curves. Critical values determined for small seedlings using CaCl2 in sand are apparently not valid for use in bareroot nurseries. At bareroot nurseries, the soil extractable Ca level can decline during a year by 30 μg g-1 or more. Harvesting 1.7 million pine seedlings may remove 20 kg ha-1 of Ca but irrigation can replace this amount or more. When water contains 5 mg l-1 Ca, 600 mm of irrigation will add 30 kg ha-1 Ca. In some areas, 1,000 mm of rainfall will supply 7 kg ha-1 Ca. Even when a Mehlich 1 test shows no exchangeable Ca in the topsoil, pine needles on tall trees may exceed 2,000 μg g-1 Ca due to root growth in subsoil. There are few documented cases of deficient pine needles (<300 μg g-1 Ca) in irrigated nurseries in Australia, New Zealand, Scotland and in the Americas. Even when soil fumigation delays the inoculation of ectomycorrhiza, bareroot pines have adequate levels of Ca. Typically, foliage samples from pine nurseries contain at least 1,000 μg g-1 Ca. Samples from 9-month-old seedlings range from 300 to 11,000 μg g-1 Ca. Although the “critical value” for Pinus echinata foliage is not known, 1-0 seedlings with 300 μg g-1 Ca were not stunted and apparently grew well after ouplanting.

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