{"created":"2021-03-01T06:14:05.190466+00:00","id":11196,"links":{},"metadata":{"_buckets":{"deposit":"32dce048-73ad-48e4-bf1b-eafaa711b6ce"},"_deposit":{"id":"11196","owners":[],"pid":{"revision_id":0,"type":"depid","value":"11196"},"status":"published"},"_oai":{"id":"oai:soar-ir.repo.nii.ac.jp:00011196","sets":["1016:1018:1103:1107"]},"author_link":["35035"],"control_number":"11196","item_10_biblio_info_6":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1999-03-08","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"46","bibliographicPageStart":"1","bibliographicVolumeNumber":"35","bibliographic_titles":[{"bibliographic_title":"信州大学農学部演習林報告"}]}]},"item_10_description_20":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"It is generally said that soil moisture condition affects the quality and production of crop or vegetables. Therefore many considerations have been made on this theme. The aim of this study is operation of the mechanism of soil moisture condition formation in upland field and its rational management to save irrigation water and so on. Volume 1: Experimental Study on The Forming Mechanism of Soil Moisture Condition in Upland Fields. In the summer of 1994, drought injury in crops occurred due to high temperature and low rainfall throughout Japan. In this study, the author examined the characteristics of soil moisture condition and evapotranspiration to determine the water balance in a maize field during the drought. The results are summarized as follows: ①The total amount of soil moisture in the soil layer to a depth of 1.0m below surface throughout the growing season was less than the Depletion of water content for Optimum growth (DOG). And soil moisture was reduced even at a depth of 2.0m, primarily because of the rapid development of the maize root systems and water uptake. ②Characteristic of the energy balance in the maize field during the growing season under the drought conditions in this study were different from results reported by others for other crops, for example the intensity of latent heat flux approximated net radiation flux, and sensible heat flux was nearly or less than zero. ③Dry matter production, total digestible nutrients and some other components were less in 1994 than 1995, when those values were comparable to values during the normal year, despite the similarities between the two years in the weather conditions for the growth of maize. This difference may be due to the difference in total amount of soil moisture below the soil surface to a depth of 1.0m at the conclusion of Baiu, the rainy season. In 1995, the soil moisture condition was higher than DOG because of high rainfall during Baiu. ④On the bases of the above findings, the authors propose a simple irrigation method. When rainfall is insufficient at the end of the rainy season, field are irrigated only a time as soon as possible to attain the field capacity in the soil layer to a depth of 1.0m below surface. Film mulch is being used in many farm lands because it improves the environment for cultivation by suppressing water evaporation from soil surface, maintaining a mild soil moisture condition, and maintaining the soil temperature higher than the bare soil surface, in addition to protecting against pests and diseases. Crop cultivation in cool high lands (such as the Shinshu Plateau) can be made possible with the introduction of film mulch. However, as the direct infiltration in the root zone are lower in fields where film mulch is used than in bare soil fields, and this raises fears that droughts would be exacerbated. Experimental comparisons of the soil moisture condition and flow between mulched bed and furrow space using the soil moisture measurement technique at many positions and many depths were carried out in the fall of 1995 in field planted with Chinese cabbage (Brassica pekinensis Rupr.), and in the spring of 1996 in field planted with cabbage (Brassica oleracea L.). The results are summarized as follows; ①The shallow topsoil of the mulched beds had less soil moisture than furrow space and bare soil even after light rains at low soil moisture condition. The sowed areas (hole of the mulch film) in mulched beds, however, were moister than the surrounding of sowed area. But one or two days after rainfall, soil moisture condition in mulched bed and furrow space were almost same. ②As the crops grew, the soil moisture became lower than furrow space due to the water uptake by the crops' root system. In the soil layer below the root zone, i.e. at a depth of more than 0.3m, soil moisture is moved from the furrow space to the mulched bed by the gradient of soil moisture potential ⊿ψ caused by the soil moisture uptake by the root system. Volume 2: Experimental Study on The Rational Management of Soil Moisture Condition to Save Irrigation Water and Rise the Crops Production and Quality. High temperature and low rainfall created drought conditions in most of Japan during the summer of 1994. The authors measured soil moisture condition and evapotranspiration (ET) rates during that time. Suzuki and Nakayama (1996) showed that the ET rate in maize under drought conditions remained constant despite the soil moisture declining to below the level for optimum growth. They explained this observation result by the rapid development of the maize root system to uptake sufficient soil moisture. In this section, the author developed a method to estimate ET in maize fields under drought conditions for determination of the optimum amount of irrigation water. The observations were carried out at the research farm of Shinshu University, on a mountain foot in Japan's Chuo Alps. The 2.5ha experimental site was planted with maize (p3732, Yukijirusi CO., Ltd.). The Bowen ratio energy balance method (BREB) was selected to determined the ET rate. Nakayama et al. (1993) presented an easy method of estimating ET from cropped fields which was modified from Davies & Allen (1973) as follows: ET=ET_<pt>[1-exp{-10.563 (M_n/M_f)}X] where ET is estimated evapotranspiration, ETpt is evapotranspiration determined by Priestley and Taylor (1972), M_n is soil moisture content in the root zone, M_f is soil moisture content at field capacity in root zone and X is an empirical constant. Priestley-Taylor model shows as follows: ETpt=αΔ(Rn-G)/(Δ+γ) Where α is an empirical constant and a value of 1.26 was used in this paper, Δ is the slope of saturation vapor pressure curve at the air temperature. This creates a modified method to estimate ET as a function of the ratio of soil moisture to total amount of available soil moisture in root zone. However, the main root zones for many crops vary during the growing season. So in this paper, the author sought to improve the method by introducing a root spread (width & depth) factor. Each maize plant at this experimental site was planted (seeded) and occupied 0.18 m2 (0.2m×0.9m) of land. The development of maize roots was observed directly by digging trenches and looking weekly or every other week during the maize growing seasons of 1994 and 1995. The soil moisture characteristic curves in the site were determined by the pressure plate method and ranged from 0.006 to 1.550MPa. Soil moisture profile was observed using tensiometers at the depth of 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0m. When some tensiometers could not use, soil was sampled down to 1.0m, about once a week, and oven dried. By the profiles of observed soil moisture profile on August 19, 1994, the soil layer down to 1.0m below the soil surface was less than the soil moisture content of depletion for optimum growth point (DOG) and the surface was near the air-dried moisture content. Root development progressed from ca. 0.6m to 1.8m depth between 70 and 110 days from seeding into the growing season. The maximum root depth (or thickness of the total root zone) (=D (m)) during the growing season (or irrigation period) of maize was expressed by the following equation as a function of plant age (d (days)): D=0.03d-1.50. As the maize root progresses to a deeper layer, the effective soil layer expands and the available soil water increases. But in this paper, the gravitational potential of soil moisture isn't considered. Combining the equations by Nakayama el al. (1993) and D determination equation give the following equation: ET=ETpt[1-exp{-10.563 (M_<nD>/M_<fD>)}X] where M_<nD> is the remainder of available soil moisture in D and M_<fD> is the total amount of available moisture in D. Available soil moisture was defined between field capacity and permanent wilting point (PWP). Denmead & Shaw (1962) showed a reduction in transpiration rate as the soil dried and that the transpiration rate was related to soil moisture suction and potential evaporation conditions. The authors try to evaluate actual ET in terms of the amount of available soil moisture for plant growth. The value of X is found to be 0.5 in this study. The components of a maize field water balance from August 12 to 19, 1994 were as follows: daily ET was 6.3×10-3m, the daily change of soil moisture in the upper 1.0m soil layer was 3.3×10-3m and the estimated upward capillary flux at 1.0m depth (daily) was 0.5×10-3m. These values show that the amount of maize root water uptake from soil layers deeper than 1.0m was about 40% of the rate of daily ET. During the 1994 and 1995 maize growing seasons, ET, determined by the equation in this study, was about 1.21 times ETpt. When soil heat flux was disregarded, that ratio became about 1.06. The value of 1.21 is similar to the ET ratio obtained in a maize field for Tokai Region, Japan (=1.3). By the comparison of actual ET (ETac) and the ET calculated by this study equation shows the equation is sufficiently accurate to estimate the actual ET of a maize field. However, there were a few samples in this study for which the actual ET was less than the ETpt. Which moisture condition decreases the actual ET remains unclear, but under usual drought conditions in Japan, for instance several successive rain free periods during the maize growing season, the simplest equation to determine the actual ET can be expressed as follows: ET=δETpt. (δ=1.06 for fodder maize when soil heat flux was disregarded) The observation results in this paper show that the actual ET rates were larger than ETpt. This is a characteristic of the heat balance of a maize field and is explained by the high plant height and large leaf area index. Almost fodder maize fields have not been irrigated even if drought damage were expected. It may come from the fact that the irrigation of maize field is very troublesome task and the effect to the harvest and quality have not been clarified so far. The author presented a laborsaving irrigation method for maize and the deep-rooted crops by the results of water balance analysis and the yield of maize in 1994, 1995 and 1996. The proposed irrigation method are shown as follows. ①Irrigation in the end of rainy season, once a growing season, is quite enough for high production. ②The amount of the irrigation water is decided in order to supply the water deficit to the field capacity in the soil from the surface to 1.0m depth. The merits of the irrigation method are as follows. ①The laborious tasks for irrigation are greatly decreased. ②This method moderates the peak demand of irrigation water by the time lad of ca. 1 week because the end of rainy season falls about one week before the peak water demand. ③The result of verifying experiment showed that maize yield under the irrigation increases about 12% more in dry matter production than that of non irrigated field. ④The methods is expected to eliminate many differences of rotating the standardized sprinkler system under the conditions of tall grass height because the plant height of fodder maize at the end of the rainy season is still low. The results in experimental study in mulched field shows in volume 1 propose that occasional plowing in the furrow space causes an increase in the infiltration rate of rain water and reduction of evapotranspiration by weeds in furrow space, and facilitates the movement of moisture from the furrow space to the root zone of the mulched beds.","subitem_description_type":"Abstract"}]},"item_10_description_30":{"attribute_name":"資源タイプ（コンテンツの種類）","attribute_value_mlt":[{"subitem_description":"Article","subitem_description_type":"Other"}]},"item_10_description_5":{"attribute_name":"引用","attribute_value_mlt":[{"subitem_description":"信州大学農学部演習林報告 35: 1-46(1999)","subitem_description_type":"Other"}]},"item_10_link_3":{"attribute_name":"信州大学研究者総覧へのリンク","attribute_value_mlt":[{"subitem_link_text":"鈴木, 純","subitem_link_url":"http://soar-rd.shinshu-u.ac.jp/profile/ja.ZUTVPpkh.html"}]},"item_10_publisher_4":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"信州大学農学部附属演習林"}]},"item_10_source_id_35":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0559-8613","subitem_source_identifier_type":"ISSN"}]},"item_10_source_id_40":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00121330","subitem_source_identifier_type":"NCID"}]},"item_1627890569677":{"attribute_name":"出版タイプ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"鈴木,  純"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2015-09-25"}],"displaytype":"detail","filename":"Agri_Forests-35-01.pdf","filesize":[{"value":"4.9 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"Agri_Forests-35-01.pdf","url":"https://soar-ir.repo.nii.ac.jp/record/11196/files/Agri_Forests-35-01.pdf"},"version_id":"830e8373-46a2-4468-a551-1707085bc2c0"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"畑地土壌水分環境の形成機構とその合理的管理方法","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"畑地土壌水分環境の形成機構とその合理的管理方法","subitem_title_language":"ja"},{"subitem_title":"Experimental on the forming mechanism of upland field soil moisture condition and its rational management to save water use and high quality production","subitem_title_language":"en"}]},"item_type_id":"10","owner":"1","path":["1107"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2012-03-07"},"publish_date":"2012-03-07","publish_status":"0","recid":"11196","relation_version_is_last":true,"title":["畑地土壌水分環境の形成機構とその合理的管理方法"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-14T03:59:01.949620+00:00"}