Abstract
In some cases of direct sowing culture in the Kanto district, there is observed a year by year decrease in yield. The purpose of this experiment is to clarify the reasons for this decrease. The experiment wes carried out on wel1-drained paddy fields from 1968 to 1970. Experimental plots were divided by the number of years of direct sowing culture-first year plot, second year plot, third year plot and long term plot, and the combination of the amount of nitrogen application-0, 12 and 18g per square meter. Results obtained are as follows : 1. Growth and yield. Both the plant growth in the early stage and the yield were greater in the first year plot than in the long term plots. However there were found of apparent differennces in these properties among the second year plot, third year plot and long term plot. 2. Inorganic nitrogen in the soil. The movement of inorganic nitrogen in the soil in the first year plot apparently differed from that in the long term plot. In the first year plot, the amount of ammoniacal nitrogen was higher and the amount of nitrate nitrogen was lower than in the long term plot, in the early stage of upland condition. Accordingly, the ratio of nitrate nitrogen to total inorganic nitrogen in the soil was lower in the first year plot. However there were no significant differences among the second year plot, third year plot and the long term plot, in relation to the amount of inorganic nitrogen and its composition. 3. These results were observed for all nitrogen applicaltion levels in this experment. 4. It may be concluded from the abovefacts, that the better growth and yield of rice in the first year of direct sowing culture are attributed to the retardation of nitrification of inorganic nitrogen inthe soi1 in the early stage of upland conditions.
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
Early-stage plant growth and yield of rice were greater in the first-year direct sowing plot than in long-term plots, at all nitrogen levels.
- Taxon
- rice
Oryza sativat0 - Treatment
- first year plote0
- Outcome
- the plant growth in the early stage and the yielde0
- Direction
- greatere0
- Qualifier
- all nitrogen applicaltion levelse1
- Comparator
- long term plotse0
- Setting
- wel1-drained paddy fieldse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e0“Both the plant growth in the early stage and the yield were greater in the first year plot than in the long term plots”
e1“These results were observed for all nitrogen applicaltion levels in this experment”
e2“The experiment wes carried out on wel1-drained paddy fields from 1968 to 1970”
Claim · model-written summary
Soil ammoniacal nitrogen was higher in the first-year plot than in the long-term plot in the early upland stage.
- Taxon
- riceOryza sativat0
- Treatment
- first year plote3
- Outcome
- amount of ammoniacal nitrogene3
- Direction
- highere3
- Qualifier
- in the early stage of upland conditione3
- Comparator
- long term plote3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e3“In the first year plot, the amount of ammoniacal nitrogen was higher and the amount of nitrate nitrogen was lower than in the long term plot, in the early stage of upland condition”
Claim · model-written summary
Soil nitrate nitrogen was lower in the first-year plot than in the long-term plot in the early upland stage.
- Taxon
- riceOryza sativat0
- Treatment
- first year plote3
- Outcome
- amount of nitrate nitrogene3
- Direction
- lowere3
- Qualifier
- in the early stage of upland conditione3
- Comparator
- long term plote3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e3“In the first year plot, the amount of ammoniacal nitrogen was higher and the amount of nitrate nitrogen was lower than in the long term plot, in the early stage of upland condition”
Claim · model-written summary
The ratio of nitrate nitrogen to total inorganic nitrogen in soil was lower in the first-year plot.
- Taxon
- riceOryza sativat0
- Treatment
- first year plote4
- Outcome
- ratio of nitrate nitrogen to total inorganic nitrogen in the soile4
- Direction
- lowere4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e4“Accordingly, the ratio of nitrate nitrogen to total inorganic nitrogen in the soil was lower in the first year plot”
Claim · model-written summary
No significant differences in the amount and composition of soil inorganic nitrogen were found among the second-year, third-year and long-term plots.
- Taxon
- riceOryza sativat0
- Treatment
- second year plot, third year plote5
- Outcome
- amount of inorganic nitrogen and its compositione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e5“However there were no significant differences among the second year plot, third year plot and the long term plot, in relation to the amount of inorganic nitrogen and its composition”
Claim · model-written summary
The authors attribute the better early growth and yield of rice in the first year of direct sowing to retarded nitrification of soil inorganic nitrogen.
- Taxon
- riceOryza sativat0
- Outcome
- growth and yielde6
- Qualifier
- retardation of nitrification of inorganic nitrogene6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rice Yield Decrease”
e6“the better growth and yield of rice in the first year of direct sowing culture are attributed to the retardation of nitrification of inorganic nitrogen inthe soi1 in the early stage of upland conditions”