Abstract
Abstract The action of N in promoting fertilizer P utilization was studied in the field and greenhouse over a period of 4 years using P 32 tagged superphosphate as the tool for uptake evaluation. Wheat and oats were used as indicator crops on several soils, employing different rates, times, and methods of application, and different forms of N and P. Fertilizer N stimulates plant use of fertilizer P throughout a wide range of soil conditions. The NH 4 + ion apparently exceeds NO 3 ‐ in this capacity, especially during early stages of plant growth, the maximum influence of either occurring with intimate association of the fertilizer N and P. In greenhouse plant production, a rate of slightly > 20 pounds of N per acre is sufficient to bring about the maximum proportionate change in fertilizer P use over soil P. With a given low rate of P application, the N effect may be as much as doubling the rate of fertilizer P use with little change in soil P use. The phenomenon apparently accounts for the reported greater early utilization of P from ammonium phosphates than from non‐ammonium bearing but otherwise similar orthophosphate compounds. There seems little doubt of a physiological function of N stimulating root activity in the absorption of fertilizer P, in consideration of several earlier works and the observations here. This, coupled with observed root concentration in the zone of joint N‐P placement could largely account for the greater fertilizer P uptake under consideration. Whatever the full explanation, this is a principle of utmost significance in plant nutrition, practical application of which probably can be obtained only with a current annual crop where fertilizing the crop at a low rate, rather than the soil at a high rate, is practiced. A related incidental finding is the high efficiency associated with side‐band placement of N + P fertilizer in small grain seedings. Such a placement has advantage over placement with the seed in that the entire quantity of N required can be supplied with the P application without endangering germination and stand under limited soil moisture conditions, while at the same time permitting the maximum N effect on fertilizer P to be manifest.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 6
Claim · model-written summary
Fertilizer N stimulates plant use of fertilizer P across a wide range of soil conditions.
- Taxon
- Wheat and oats
Avena sativa
Triticum aestivume1 - Treatment
- Fertilizer Ne2
- Outcome
- plant use of fertilizer Pe2
- Direction
- stimulatese2
- Setting
- a wide range of soil conditionse2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Wheat and oats were used as indicator crops on several soils”
e2“Fertilizer N stimulates plant use of fertilizer P throughout a wide range of soil conditions”
Claim · model-written summary
The NH 4 + ion exceeds NO 3 ‐ in stimulating fertilizer P use, especially during early plant growth.
- Taxon
- Wheat and oatsAvena sativaTriticum aestivume1
- Treatment
- NH 4 + ione3
- Outcome
- capacitye3
- Direction
- exceedse3
- Qualifier
- especially during early stages of plant growthe3
- Comparator
- NO 3 ‐e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Wheat and oats were used as indicator crops on several soils”
e3“The NH 4 + ion apparently exceeds NO 3 ‐ in this capacity, especially during early stages of plant growth”
Claim · model-written summary
A rate of slightly more than 20 pounds of N per acre gives the maximum proportionate change in fertilizer P use over soil P in greenhouse production.
- Taxon
- Wheat and oatsAvena sativaTriticum aestivume1
- Treatment
- a rate of slightly > 20 pounds of N per acree4
- Outcome
- proportionate change in fertilizer P usee4
- Direction
- maximume4
- Setting
- greenhouse plant productione5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Wheat and oats were used as indicator crops on several soils”
e4“a rate of slightly > 20 pounds of N per acre is sufficient to bring about the maximum proportionate change in fertilizer P use over soil P”
e5“In greenhouse plant production”
Claim · model-written summary
With a low rate of P application, N may double the rate of fertilizer P use with little change in soil P use.
- Taxon
- Wheat and oatsAvena sativaTriticum aestivume1
- Treatment
- Ne5
- Outcome
- rate of fertilizer P usee5
- Direction
- doublinge5
- Qualifier
- may bee5
- Comparator
- soil P usee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Wheat and oats were used as indicator crops on several soils”
e5“With a given low rate of P application, the N effect may be as much as doubling the rate of fertilizer P use with little change in soil P use”
Claim · model-written summary
N stimulates root activity in the absorption of fertilizer P in wheat and oats.
- Taxon
- Wheat and oatsAvena sativaTriticum aestivume1
- Outcome
- absorption of fertilizer Pe6
- Qualifier
- physiological function of N stimulating root activitye6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Wheat and oats were used as indicator crops on several soils”
e6“There seems little doubt of a physiological function of N stimulating root activity in the absorption of fertilizer P”
Claim · model-written summary
Side-band placement of N + P fertilizer in small grain seedings has a high efficiency, with an advantage over placement with the seed.
Verbatim
e7“the high efficiency associated with side‐band placement of N + P fertilizer in small grain seedings”
e6“Such a placement has advantage over placement with the seed”