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Volume 40 (2005)
- Issue 4 Pages 183-
- Issue 3 Pages 141-
- Issue 2 Pages 67-
- Issue 1 Pages 3-
Volume 40, Issue 2
Displaying 1-6 of 6 articles from this issue
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Tatsuo SATO, Kyoko MATSUURA, Rika TAKAYANAGI, Yutaka YONEYAMA2005 Volume 40 Issue 2 Pages 67-72
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSDownload PDF (793K) -
Tatsuo SATO, Toru FURUGOORI, Rika TAKAYANAGI, Yutaka YONEYAMA2005 Volume 40 Issue 2 Pages 73-78
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSThe practical adaptability of a formula for estimating the amount of absorbed nitrogen (absorbed nitrogen (g/m2/14 days)=increased leaves (no./m214 days) ×0.0383+1.856) was tested as a fertilization index in autumn cucumber, cultivated using drip tubes, in a commercial greenhouse. Ammonium nitrate and potassium nitrate were used as nitrogen sources.
First, the total applied nitrogen was -1.8kg/a on both sides of the greenhouse. The final marketable yields were 543-615kg/a, i. e., the same as those produced by means of conventional cultivation, although markedly less nitrogen fertilizer was used. The NO3-N level in the soil was kept under 20mg/100g throughout the period. No nitrogen remained in the soil because fertilization was stopped one month before the end of harvest.
Second, the distribution of EC and pH throughout the field was estimated. The variation of the EC distribution may have been due to unequal nitrogen application before the introduction of drip fertilization, which improved distribution. Conversely, drip fertigation did not improve the variation in pH, because no basic elements were applied in this system.
In conclusion, our formula should be used to estimate the amount of nitrogen to apply. This saves fertilizer, while providing sufficient yields and controlling the unequal distribution of EC in autumn cucumber raised using drip tubes.View full abstractDownload PDF (1096K) -
Hiroyuki TSUJI, Yasuo OHSHITA, Jiro WATANABE, Rintaro OKUNO2005 Volume 40 Issue 2 Pages 79-88
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSA 2-year field study was conducted during 2002 and 2003 to determine the impacts of spring sown winter wheat (Triticum spp.) living mulch and soybean (Glicine max (L.) Merr.) planting density on weed control and soybean yield at Hokkaido upland field. The experimental design in 2002 was consisted of 2 wheat sowing densities (0g/m2: MC and 16g/m2: 16M) and 2 soybean planting densities (conventional: CP, 16 plants/m2 and dense: DP, 24 plants/m2) with pre-emergent herbicide application in all plots. The experimental design in 2003 was consisted of 3 wheat sowing densities (0g/m2 and mechanical control to weed: MC, 16g/m2: 16M and 8g/m2: 8M) and 3 soybean planting densities (conventional: CP, 17 plants/m2, sparse: SP, 12 plants/m2 and dense: DP, 28 plants/m2) without herbicide. Soybean yields were lower in the 8M and 16M plots compared with the MC plots. In the DP plots, however, reductions in yield were less significant, especially in 2003. Living mulch showed a remarkable effect on weed control in the DP plots, however, in 2003 the mulch was unable to sufficiently control emergence and development of tufted knotweed (Persicaria longiseta (De Bruyn) Kitag) and Persicaria lapathifolia (L.) S. F. Gray, since the weeds emerged prior to the soil surface being covered by the mulch and soybean leaves. These results indicate that adequate soybean plant density and pre-emergent herbicide application are requirements for weed management and satisfactory yield in soybean production systems that use wheat living mulch.View full abstractDownload PDF (1307K) -
Takeshi HIDA, Hirofumi KUBOTA, Satoshi YONEKAWA2005 Volume 40 Issue 2 Pages 89-96
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSNo-tillage culture is useful to reduce energy consumption, but it is often associated with degradation of soil physical properties leading to yield loss. The effects of sorghum (Sorghum bicolor L.) as a summer cover crop on infiltration of soil were investigated by analysis of the relationship between precipitation and soil water content. When the sorghum grew well, reaching a height of about 180cm, soil infiltration was improved because soil water content was favorable, while total precipitation became about 50mm at an initial soil water content of 50%db. In contrast, when the sorghum showed insufficient growth with a height of about 40cm, soil infiltration was not improved. The effects of sorghum on soil infiltration are bigger and lasted longer than the effects of mechanical tilling. The improvement of soil infiltration by sorghum contributes to prevent yield decrease in subsequent buckwheat (Fagopyrum esculentum Moench) culture.View full abstractDownload PDF (1863K) -
Tadashi CHOSA, Masaaki OMINE, Hisashi HOSOKAWA, Kan ARAKI2005 Volume 40 Issue 2 Pages 97-103
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSThe objective of this research was to develop a sub-measurement unit that integrates the serial data from a GPS device and signals from various sensors triggered by the GPS signal. Since the unit uses a commercially available microcomputer, it can easily be used to build inexpensive measurement systems consisting of a data-logging unit, the sub-measurement unit, a GPS device, and various sensors whose output signals are analog or pulse signals. The sub-measurement unit can be used to integrate signals by simply connecting the GPS device and sensors.
This report discusses, as examples of application of the unit, systems for measuring yield and slip ratio. Results of field experiments showed that these systems could be used for acquiring combine harvesting data and rotary tillage data.
The sub-measurement unit is not limited to systems measuring yield and slip ratio or by the requirement that the sensor signals be either analog or pulse signals. It can therefore be used to set up systems that gather various kinds of data (concerning, e. g., crop growth, machine operation, labor intensity, and the working environment) and integrate this data with positional information. A wireless modem for data logging can also be incorporated into the unit.View full abstractDownload PDF (1846K) -
2005 Volume 40 Issue 2 Pages 105-126
Published: June 15, 2005
Released on J-STAGE: February 09, 2010
JOURNAL FREE ACCESSDownload PDF (3888K)
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