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群落表面温度から気温を引いた値である葉気温較差 (ΔT) は, 作物品種のかんばつ回避性を圃場条件下で簡便かつ非破壊的に推定できる指標であることが, 大気飽差 (VPD) が比較的大きい, 乾燥した国々での実験で報告されている. 本研究では, VPDが比較的小さい日本の圃場条件下においても, ΔTをかんばつ回避性の指標として用いることが可能か否かを検討した. なお, かんばつ回避性は気孔コンダクタンス (gs) と葉内水分ポテンシャル (LWP) を無灌水条件下においても灌水条件下と同様に高く保つ能力と定義した. かんばつ回避性が大きく異なることが想定されるテンサイ, バレイショおよびイネ (水稲用および陸稲用品種) を, 降雨を遮断して灌水と無灌水の2種類の土壌水分処理を行った畑圃場で供試した. 植付けもしくは移植の7週間後から5週間, サーモグラフィー装置を用いて群落のΔTを測定し, 同時にgsとLWPを測定した. 無灌水区ではΔTに有意な作物間差が認められ, イネ水稲用品種で最も高く, イネ陸稲用品種, バレイショ, テンサイの順で低くなった. また, gsおよびLWPについても有意な差異が認められ, ΔTとは逆にテンサイで最も高く, バレイショ, イネ陸稲用品種, イネ水稲用品種の順で低くなった. 一方, 灌水区では, これら3形質における作物間差は相対的に小さかった. 3形質のいずれにも, 土壌水分処理と作物との間に有意な相互作用が認められた (いずれもp, The difference between canopy temperature and air temperature (ΔT) is reported to be a convenient criterion for the non-destructive evaluation of drought avoidance of crop varieties under field conditions in arid countries, where vapor pressure deficit (VPD) is high. We examined its validity under field conditions in Japan, where VPD is low. We defined the drought avoidance as the ability to maintain stomatal conductance (gs) and leaf water potential (LWP) under non-irrigated conditions as high as those under fully irrigated conditions. Four crops (sugar beet, potato and two rice genotypes of upland and lowland), which were assumed to be greatly different in drought avoidance, were grown in both fully irrigated and non-irrigated fields under a rain shelter. For five weeks starting from the 7th week after planting, ΔT was measured by infrared thermography, in concurrence with the measurement of gs and LWP. In the non-irrigated plot, ΔT, gs and LWP differed significantly among the crops; lowland rice showed the highest ΔT and the lowest gs and LWP, followed by upland rice, potato and sugar beet. Meanwhile, in the irrigated plot, their differences were relatively small. There was significant interaction between irrigation treatment and crop in ΔT, gs and LWP (all p

application/pdf, Harvesting of rice with volunteer weeds and threshing for rice grams by Kyaukto, a pillow-like device, which is made of Palaeozoic limestone, were found in the upland rice fields near 12 and 29 km northern to Kalaw, Shan state in Shan Highlands of Myanmar. Rice was frequently harvested with volunteer weeds and relic millets such as Setaria italica, and Echinochloa sp. in the area. The Kyaukto device was used for threshing rice grains by an ethnic minority, the Taungyo, belonging linguistically to the ancient Burmese family. Several female persons harvested upland rice at the bottom by a small-size sickle to bind and carry rice bundles with ears to the threshing place (ca. 10 m by 10 m) covered with 16 sheets of bamboo carpets. On the threshing carpets, nine, young, barefooted male persons had standing positions on the circle facing to the center, and each man beat the rice bundles on the stone. The stone was set with two bundles of rice straws ringed compactly in order to keep the stone surface at an angle of 30 degrees. Rice grains were gathered and the unnecessary parts were removed skillfully by a bamboo stick. Finally, two female persons winnowed the rice grains and got rid of dusts and trashes for cleaning., 大阪府立大学大学院農学生命科学研究科学術報告. 2001, 53, p.37-40

This exploration mission was undertaken to collect rice germplasm in the two provinces, Thanh Hoa and Nghe An of northern Vietnam from November 5 to December 4 in 1996. A total of 154 seed samples were collected. Most of them are glutinous landraces of upland rice. Landraces cultivated in irrigated fields have been replaced by improved cultivars, CR203 and IR17494 and hybrid rice from China, even in mountainous regions. Arable lands of upland rice have decreased in these two provinces because of a shift to other crops.

世界中には多くの乾燥・半乾燥地が存在するが,アフリカ,とくにサブサハラ・アフリカ地域は貧困かつ砂漠化の被害を受ける危険性が最も高い地域であり,農業を営む上で「水」と「土壌栄養」の絶対量が不足している。そこで本研究では,同地域における農業生産に寄与することを想定して,現地で入手可能な有機質資材を活用したマルチによる土壌水分蒸発抑制効果を検討すべく,次の試験を実施した。(1) 塩ビ製カラムに無マルチ,有機質資材マルチ(ソルガム残渣被覆および木材チップ被覆)3種類の処理を施し,それぞれ減少した質量から蒸発量を測定した。(2) 陸稲を栽培した1畝当たり6.5m×0.8mの試験区を設置し,灌漑水量を標準灌漑で3～6mm/日,節水灌漑で,標準区の1/2の1.5～3mm/日とし,無マルチ区と有機質資材マルチ区(ソルガム残渣被覆,木材チップ被覆)の土壌水分移動状況について実測するとともに,生育へ及ぼす影響を検討した。両実験の結果では,ソルガム残渣または木材チップを施したカラムの蒸発量は無被覆よりも少なく,とくにソルガム残渣を用いたカラムでは顕著であった。さらに陸稲の生育・収量結果から,ソルガム残渣または木材チップの有機質資材マルチが初期生育および出穂促進にも効果が見られた。, There are many semi-arid and arid areas in the world, but Africa, particularly Sub-Saharan Africa, is one of the most vulnerable regions under the threat of desertification. This problem is further compounded by insufficiency in agricultural water use and declining soil fertility. In this study, the following test was conducted with the objective of contributing to agricultural production in the region by utilizing locally available organic material mulches in controlling soil moisture evaporation.i) The evaporation control test was carried out in three columns made of PVC with each column consisting of three different treatments, namely organic material mulching with sorghum stalk residues, lumber chips and non-mulching. The amount of evaporation from the reduced mass was determined for each of these treatments.ii) Upland rice was cultivated at each plot of 6.5 m long and 0.8 m wide. Four plots were divided into 2 groups based on the amounts of irrigation ; one was irrigated at 3 to 6mm/day (Standard plot) and the other at 1.5 to 3mm/day (1/2 water saving plot). Each group was constituted with 3 different treatments as organic material mulching with sorghum stalk residues, lumber chips and non-mulching. Soil moisture was measured by TDR soil moisture sensor, and the impact on plant growth monitored.Results of both experiments showed that evaporation from the organic material mulching with sorghum stalk residues and lumber chips were smaller than non-mulching. Organic material mulching test plots with sorghum stalk residues showed remarkable results. In addition, it became clearer that organic material mulching plots were better than those that were not mulched in terms of their potential effectiveness in promoting early growth and heading of upland rice.

本研究は,東京農業大学内のエコテクハウスにおいて,雨水利用節水灌漑システムにおける水収支および節水灌漑方法と灌漑効果について検討したものである。今回,ハウス内で栽培した作物は灌漑効果が高いといわれている陸稲である。試験結果からみて,灌漑水量,湿潤域内における土壌水分増加量,消費水量および灌漑効果に関して以下のように要約される。(1) 標準区(消費水量相当量灌漑区) : 土壌水分増加量は灌漑水量よりも多く,消費水量も灌漑水量よりも多くなり,土壌水分量は十分に供給され,陸稲の生育・生体重とも他の2試験区に比べて多い結果であった。(2) 中間区(標準区の75%灌漑区) : 土壌水分増加量は灌漑水量よりも多く,消費水量は計画用水量に近似し,陸稲に必要な水分は供給された。生育・生体重とも標準区と比べて遜色ない結果であり,節水灌漑からみて灌漑効果を維持し,灌漑水量の節減につながる可能性をみいだせた。(3) 節水区(標準区の50%灌漑区) : 土壌水分増加量および消費水量とも灌漑水量よりも少なく,水分不足が発生した。生育・生体重結果からみても他の2試験区と比べて劣り,極端な節水灌漑は,本来の畑地灌漑の効果からみて問題であるといえる。以上の灌漑試験結果から,標準灌漑水量の75%で灌漑効果を維持しつつ用水の節減につながる可能性があると判断される。, The objective of this study is to evaluate water saving effect of the new water saving irrigation system which used rainwater as irrigation water and solar energy for saving water and energy use in a greenhouse. In the green house, upland rice was cultivated under three different irrigation intensities, (i) same intensity as expected consumptive water use (standard plot), (ii) 75% of the irrigation intensity of (i) (medium saving plot), (iii) 50% of that of (i) (saving plot). Soil water contents were monitored to clarify the water balance and the soil water distribution in each plot distribution. From the results of the calculation, consumptive water use in the standard plot was higher than the amount of irrigated water. Growth and live weight of upland rice in the standard plot were higher compared with the other plots. Soil moisture in medium saving irrigation plot seemed to be also enough for upland rice cultivation because the calculated consumptive water use was nearly equal to the amount of irrigated water. Growth and live weight in medium saving plot leached those in the standard plot. But in the saving plot, consumptive water use was less than the amount of irrigated water and the growth and live weight were less than those of the other plots.