Excess-Moisture Injury Research Articles

コムギ湿害対策のための肥効調節型肥料の基肥時土壌表層施用ならびに速効性窒素追肥の効果

コムギ湿害対策のための肥効調節型肥料の基肥時土壌表層施用ならびに速効性窒素追肥の効果

地下水位制御システム（FOEAS）設工ほ場における設定水位が秋まきキャベツの生育に及ぼす影響

地下水位制御システム（FOEAS：Farm-Oriented Enhancing Aquatic System）を施工した水田転換畑において，設定した地下水位が土壌水分量，気相の酸素濃度，秋まきキャベツの生育に及ぼす影響を評価した．地下水位を-30 cmに設定した高水位区，-60 cmに設定した低水位区を設けた．低水位区では高水位区よりも高い土壌水分吸引圧で推移したが，それは最大約40 kPaまでの緩やかな増加であった．両区とも，降水量に応じて地下水位が上昇した．降雨による土壌水分量の増加と地下水位の上昇に伴って気相率だけでなく作土の酸素濃度が低下し，特に高水位区では生育後期にしばしば0％まで低下した．冬季には，高水位区において土壌水分が高く維持された結果，低水位区よりもやや鉛直投影面積が大きかったが，後期には生育が抑制され，最終的な結球重は低水位区の約60％と小さかった．従って，FOEASが施工された水田転換畑において地下水位を高く一定に設定することは，湿害の危険性を増し，キャベツ収量を低下させる可能性が高いと考えられた．

밭전환 논에서 심토파쇄에 따른 사료용옥수수의 수량성 변화

밭전환 1년차 논의 토양물리성 악화를 개선하고 사료용 옥수수 생육을 증진시키기 위한 심토파쇄의 효과를 살펴본 결과 다음과 같은 결과를 얻었다. 1. 심토파쇄에 의해 토심 25~35 cm 층위의 토양의 경도가 크게 감소하였고 토층 15~30 cm에서 가밀도, 공극율 및 고상비율 등 하층토의 토양물리성이 개선되는 것으로 나타났다. 2. 심토파쇄 추가 시 옥수수의 간엽 및 이삭의 생육이 크게 증가하였으며, 특히 이삭당 립수의 증가가 이삭중을 크게 증가시키는 것으로 나타났다. 3. 심토파쇄 추가 시 옥수수는 이삭 및 간엽의 수량증가에 의해 TDN 수량이 19~39% 증가하였으며, 특히 습해에 의해 생육이 불량한 2011년도의 옥수수의 생육촉진 효과가 컸다. Low silage corn yield due to bad soil physical properties in the paddy field converted to upland condition is the chief obstacles to expanding the area for silage maize production. The effect of subsoiling (subsoiling to depth 40 cm) on soil physical properties and silage corn yield were investigated in the first year of paddy field converted to upland condition in 2010 and 2011, respectively. Soil compaction was loosened much particularly at depth 25~35cm as much as 1~1.5 MPa and soil bulk density and porosity at depth 15~30 cm are improved by subsoiling. Maize growth was increased by subsoiling, particularly in kernel number per ear which increased ear weight. Total digestible nutrients (TDN) yield of silage maize was increased as much as 19 and 39% in 2010 and 2011, respectively showing that yield increase according to subsoiling was higher when maize growth was prohibited much by excess-moisture injury due to heavy rain in 2011.

Rotary Tilling and Ridge-Making Methods for Heavy Clay Soil

In wet rice fields with heavy clay soil, the decrease of the rate of soil pulverization and excess moisture injury are major constraints on the cultivation of vegetables as alternative crops. Deep tillage which is very important for the consolidation of the paddy field soil structure leads to the decrease of the soil pulverization and small clod rates, resulting in the increase in power requirement. In this study, implements based on a reverse-rotating tiller (up-cut rotary tiller) equipped with tines differing in length, were developed. The use of the implements enabled to perform deep tillage in the ridges and shallow tillage in the inter-ridge spaces. It became possible to cultivate soil and make ridges simultaneously. The working efficiency was 2-3 times higher than that by other methods. Also the trafficability of the implements in the inter-ridge spaces was improved. The developed implements did not require a large amount of power and did not lead to a decrease in the soil pulverization rate. The rooting zone of the ridges expanded and the soil water content inside the ridges decreased. Furthermore, the oxygen concentration in the ridge soil increased and cabbage yield increased.

Is Chinese Milk Vetch Useful as Green Manure for Summer Buckwheat Cultivation?

Summer buckwheat (Fagopyrum esculentum Moench. cv. Kitawasesoba, summer ecotype) was cultivated from April to June in 1998 in the drained paddy fields of two experimental sites:Hojo city, in the plain area facing the Inland Sea of Japan (Setonaikai), and Honjo village, in the intermediate mountainous area of Kyushu. Two types of experimental fields were prepared on both sites:a field left fallow during winter (fallow plot) and that on which Chinese milk vetch (Astragalus sinicus L.) was cultivated in winter as green manure (Chinese milk vetch plot). In 1997, a Chinese milk vetch plot was also provided in Hojo city. Because the precipitation during summer buckwheat cultivation in 1997 was low, grain yield exceeded 250 g / m2. Because of abundant rainfall around seeding time, however, the establishment percentage was very low and plant growth was markedly poor in 1998. The depression of the establishment of seedings and growth were severer in the fallow plot than in the Chinese milk vetch plot. Grain yield in the fallow plot was nearly zero, while it was 112g / m2 (47% of 1997) in the Chinese milk vetch plot. In Honjo village, the amount of rainfall during the period from flowering to maturing in 1998 was 2.76 times greater than in a normal year. Subsequently, because of the decreased number of grains per plant, grain yields in both plots showed low levels, such as 219g / m2 in the Chinese milk vetch plot and 143g / m2 in the fallow plot. As mentioned, the depression in grain yield caused by excessive soil moisture around seeding time or after flowering period was demonstrated to be severer in the fallow plot that in the Chinese milk vetch plot. These results suggest that Chinese milk vetch as green manure is useful for summer buckwheat cultivation and that excess moisture injury to summer buckwheat is considered to be reduced by the use of Chinese milk vetch.

Breeding of Two-Rowed Naked Barley Varieties with BaYMV Resistance.

Six-rowed, naked barley varieties, which are grown in western Japan, are generally susceptible to scab and excess soil moisture injury. For hulled varieties, two-rowed varieties are more tolerant to these injuries than six-rowed varieties are. Therefore two-rowed, naked varieties with good agronomic characters and BaYMV resistance, named YNH-2 and YNH-3, were developed through backcrossings. An intermediate parent, Hakei N107, was developed from the cross of Hiproly/2*Saikai kawa 12//Daisen Gold. Another intermediate parent, NHS-1, was developed from the cross of Hakei N107/Hakei P20. YNH-2 was developed from the cross of Daikei R2264/NHS-1. BaYMV resistance was derived from Daikei R2264, and YNH-3 had nearly the same pedigree as YNH-2. The grain yield of YNH-2 and YNH-3 was same as two-rowed, hulled check varieties. Grain quality was good. At present, two-rowed naked varieties are not grown in Japan, but YNH-2 and YNH-3 would contribute a more stable production of naked barley. The cold tolerance of YNH-2 and YNH-3 was moderate, incdicating that nakedness and lack of cold tolerance were not always associated, as previously mentioned.

Excess Moisture Injury of Soybeans Cultivated in an Upland Field Converted from Paddy. V. Supplemental nitrogen application as a countermeasure against excess moisture injury.

The purpose of this experiment was to examine whether the application of nitrogen (N) fertilizer as ammonium sulfate is an effective countermeasure against excess moisture injury of soybeans [Glycine maz (L.) Merr.]. Soybeans (cv. Tamahomare) were grown in an upland field converted from paddy. Flooding treatment was conducted in furrows to a depth of 5 to 8 cm for 8∼11 days at flower-bud differentiation stage and subsequently fertilizer was applied at the rate of 12 g N per m2. In the flooding plot without supplemental N, seed yield decreased by 20% ; however, in the flooding plot with supplemental N, seed yield decreased only by 6%, since the decreases in pod number were low. The reasons for the low reduction in pod munber were examined in a pot-cultured experiment. Plants under excessive soil moisture and without supplemental N had low N content in the leaf blade which brought about a marked decrease in the photosynthetic rate. In contrast, supplemental N increased the N content in the leaf blade and photosynthetic rate. It was assumed that the increased photosynthetic rate by supplemental N inhibited bud, flower and pod shedding.

Excess moisture injury of soybeans cultivated in an upland field converted from paddy. IV. The significance of nodulation under excess moisture condition.

The purpose of this experiment was to clarify the significance of nodulation of soybeans (Glycine max (L.) Merr.) under the excess moisture condition. A pair of nodulating and non-nodulating lines, T202 and T201, were grown in an upland field converted from paddy. Flooding treatments were made in the furrows to the depth of 5 to 8 cm for 8 to 10 days at three different stages: the flower-bud differentiation, the flowering and the ripening. Nitrogen content in the leaf blade and dry matter production of both lines were decreased by the treatments in all stages, however those of T202 were not reduced so much as those of T201. At the flower-bud differentiation and the flowering stages, leaf nitrogen content and dry matter production of T202 recovered to the level of the control within 15 days after the end of the treatments, while those of T201 did not. Decrease in dry matter production induced by the treatments caused the decrease in seed yield, but seed yield of T202 was not reduced so much as that of T201. These differences in two lines were attributed to whether or not fixed nitrogen could be supplied by root nodules. As mentioned above T202, a nodulating line, could reduce excess moisture injury and could soon recover from it. Therefore, it can be proved that root nodules play an important role to reduce the excess moisture injury.

Excess moisture injury of soybeans cultivated in an upland field converted from paddy. III. Foliar application of urea as countermeasure against excess moisture injury.

Excess moisture injury of soybeans cultivated in an upland field converted from paddy. III. Foliar application of urea as countermeasure against excess moisture injury.

Excess moisture injury of soybeans cultivated in a upland field converted from paddy. II. Effects of excessive soil moisture on bleeding, stomatal aperture and mineral absorption.

Using the same materials as reported in the previous paper, effects of excessive soil moisture on bleeding, stomatal aperture and mineral absorption of soybeans (c.v. Tamahomare) were studied. The earlier the growth stage was, the greater were the effects of excessive soil moisture on bleeding, stomatal aperture and mineral absorption. Soybeans were damaged not only by excess moisture but also by drought when they were grown under excessive soil condition followed by insufficient precipitation at the early growth stage when the plant community was not well developed such as at the early stage of flower-bud differentiation. This was because new roots which emerged during the treatment were damaged. Therefore, sufficient precautions must be taken against excess moisture injury at the early growth period, and in case drought damage is predicted, irrigation seems to be an effective practice.

Excess moisture injury of soybeans cultivated in a upland field converted from paddy. I. Effects of excessive soil moisture on dry matter production and seed yield.

Excess moisture injury of soybeans cultivated in a upland field converted from paddy. I. Effects of excessive soil moisture on dry matter production and seed yield.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crops. : XIII. Difference between italian ryegrass and oats in the tolerance against excess-moisture injury.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crops. : XIII. Difference between italian ryegrass and oats in the tolerance against excess-moisture injury.

Studies on Ripening of Wheat and Barley in the Warmer Districts in Japan : 3. Relationship between ripening of wheat and barley and soil moisture content.

In order to clear the effect of excess soil moisture in ripening stage on grain quality of wheat and barley, pot-experiments were carried out from 1957 to 1960. The results were summarized as follows: 1000-grain-weight of kernel raised from the soil with air porosity below about 20 volume-percent of soil was significantly inferior to one from the control plot with larger air porosity. The lowering in production in the plot holding higher soil moisture was due to smaller air capacity, higher acidity and lower redox-potential of soil. In consequence, the plant grew poorly and declined in respiration and water absorption activities. The excess soil moisture in the first half of ripening stage was mose injurious than that in the second half on plant growing. High temperature encouraged excess soil moisture injury to plant ripening. The conclusion above-mentioned was supported by surveying those points in some practical wheat fields around Chikugo Area.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants : XII. Comparative studies on the gas content and oxygen concentration in the roots of lowland and upland plants.

It is ascertained that the specific gas content in the roots is varied according to the degree of development of the ventilating system, indicating that lysigenous intercellular spaces in the roots serve as the air canal in the course of oxygen transportation from the top.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants : XI. Effect of removal of the top part of plant on respiration intensity of the roots

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants : XI. Effect of removal of the top part of plant on respiration intensity of the roots

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants : X. Effect of removal fo the top part of plant on nitrate reduction by the roots

The attached roots as well as the detached roots of both rice and soybean plants were used for the comparison between respiration intensity, as measured by carbon dioxide output, under aerobic and anaerobic conditions. The results obtained are ds follows: (1) The attached roots of rice are able to respire almost aerobically even if they were kept in a medium. containing no oxygen, in spite of the detached roots being appreciably depressed in their respiration intensity under the same condition, eventually producing carbon dioxide for the most part due to anaerobic respiration. However; there occurs no marked difference in respiration intensity between the two kinds of roots, as far as they are growing in an oxygenated medium. (2) The roots of soybean are no sooner placed under the condition of poor aeration than they are depressed in their capacity to respire aerobically. It is no doubt that carbon dioxide evolved in this case should be as a result of anaerobic respiration. When the roots are kept in an oxygenated medium, on the cotrary, the rate of carbon dioxide output is definitely higher than when they are kept in a medium under poor aeration, regardless of whether they are connected with the top or removed from it. (3) These results indicate that in the plants which are equipped with the well-developed ventilating system, the roots are able to respire aerobically even if they were met by a condition of poor aeration, because of their possibility of receiving molecular oxygen from the top and, on the other hand, in the plants which are equipped with the feebly-developed ventilating system, the roots are incapable of carrying on aerobic respiration in case of being met by the same condition, eventually producing carbon dioxide quite anaerobically.

Studies on the water lodging injury of fruit trees from the view point of soil chemistry

In the present paper, the results of the experi-ments on the relation between oxidation-reduction potentials, Fe.. and H25 contents in soils, and the submersion tolerance or excess-moisture injury of the fruit-tree roots are reported with special reference to fig, peach, pear, apple, persimmon and grape. The results are summarized as follows. 1. The growth of fruit-tree shoots were stopped by excess-moisture or water-lodging in the soils having following values of Eh6 Fig 360_??_370m. v. Peach 330_??_350m. v. Pear and Apple 260_??_280m. v. Persimmon 200m. v. Grape 170_??_180m. v. Shoot growths of pear, apple, persimmon and grape were inhibited gradually from the neigh-bourhood of ca. 300m. v. 2. Fe..-formation in soils increased as the oxi-dation-reduction potentials failed, and the amount of Fe.. extracted by HCl (pH 3) solution was ca. 20mg at 300m. v., ca. 30mg at 200m. v. and 60_??_70mg at 100m. v., per 100g. dry soil. There-fore, the root system of fig or peach was impeded mainly by oxygen-deficiency before Fe.. was formed abundantly in soil. On the other hand, the impediment of root system in the case of pear or apple was derived from a large amount of Fe.. formed by remarkable reduction in soils, and moreover, when approximately 30 mg Fe..was formed in soils on persimmon or grape. 3. When the soils were water-lodged, the higher organic matter content in soil, the more rapid Eh falling and more the amounts of Fe.. and HsS formed. Accordingly, the more high organic matter content in soil, the more remarkable the injury of root system of fruittree caused by excess-moisture. 4. Fig and peach were susceptible, pear was middle and grape and persimmon were resistant. Parallelism between resistance of root system to Fe.. and H2S, and submersion tolerance of root was found. And it was suggested that the differ-ence of resistance to excess-moisture injury was caused by the difference of oxidation power of root towards the exterior.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crops. : VII. Comparative studies on the ventilating pressure in lowland and upland rice plants growing under flooded and under water economized conditions. : VIII. On the ventilating system and the ventilating psessure in various plants growing on lowland and on upland.

Further studies were made on the ventilating system in various plants in relation to the ventilating pressure, the results being summarized as follows: 1) A highly developed ventilating system was observed in various lowland plants, wherever they might be grown, They exhibited a lower ventilating pressure, varying almost in accordance with the metabolic activity of their roots. 2) On the contrary. feebly developed ventilating systems were observed in upland plants, as far as they were growing under dry conditions. They could accomodate themselves to over-moist haditats, by means of reconstructing the ventilating system likely enough to make it possible for their roots to receive considerable amounts of oxygen from their tops. Considerable degrees of reformaticn in the ventilating system and renewal of the root system were observed when they met with over-moist conditions. 3) Referring to the POISEUILLE's and FICK's laws, a theoretical explanation of the relation between the significance of the ventilating pressure and the gaseous diffusion from the top to the root was presented. Explanation of figures The dotted portions in all the figures refer to the intercellular spaces containing much air or the tissue having those spaces. The abbreviations are as follows : Ca, cavity; co, cortex or hypodermis; en, endodermis; ep, epidermis; ha, hair; ly, lysigenic space; pi, pith; rh, root hair; rv, reinforced vascular bundle; sv, separated vascular bundle; sz, sizogenic space; va, vascular bundle. Rice plant (common to the lowland and upland rice pldnts). Fig. 1. Internode of the peduncle. Fig. 2. The 1st internode (the uppermost). Fig. 3. The 2nd internode. Fig. 4. The 3rd internode. Fig. 5. The 4th internode (the lowest elongated one). Fig. 6. Not elongated internode in the 5th order. Such an internode is a component of the so-called tillering portion, totaling about 12 internodes in succession. Barn-yard grass and other grasses. Fig. 7. Internode of the peduncle. Fig. 8. The 2nd internode. Fig. 9. The 4th internode. Fig. 10. The 6th internode (the lowest elongated one). Fig. 11. The stem of Ranunculus sceleratus. Fig. 12. The stem of Veronica Anagallis. Corn plant growing on upland (12 leaf-stage). Fig. 13. Middle portion of the 4th green leaf-sheath. Fig. 14. The 4th node to which the 4th green leaf-sheath is attached. Fig. 15. The 6th internode. Fig. 16. Root zone with a crown root. Fig. 17. Basal portion of a crown root. Fig. 18. Middle portion of the crown root. Corn plant kept flooded (12 leaf-stage). Fig. 19. Middle portion of the 4th green leaf-sheath. Fig. 20. The 4th node to which the 4th green leaf-sheath is attached. Fig. 21. The 6th internode. Fig. 22. Root zone with a crown root. Fig. 23. Basal portion of a crown root. Fig. 24. Middle portion of the crown root.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants. : V. Various Forms of the Ventilating System in Wheat, Barley and Some Forage Crop Plants

Microscopic observations have revealed that the crop plants tolerant against the injury of excessive soil moisture are characterized with a highly developed ventilating system and that the reverse is true for those susceptible. The ventilating system may furnish the crop root with sufficient oxygen transported from the top. In the illustration figures of the present report the following abbreviations are used: Ab, axillary bud; ae, aerenchyma ; ca, cavity; ck, cork; co, cortex; cr, crown root; en, endodermis; ep, epidermis; ls, leaf-sheath; ly, lysigenic air space; pa, partition, pe, pericycle; pm, primary meristem; rv, reinforced vascular bundle; sm, secondary meristem; sp, sieve portion; St, stipula; sv, separated vascular bundle; va, vascular bundle; wp, wood portion.

Studies on the Development of the Ventilating System in Relation to the Tolerance against Excess-Moisture Injury in Various Crop Plants. : IV. The Ventilating Pressure in the Rice Plant Growing in Paddy-Field Conditions.

Potted plants of the lowland rice variety, Norin 37, were used for the measurement of the ventilating pressure at intervals of bout 2 weeks after transplanting. The results obtained are as follows: 1. The ventilating pressure varied with the degree of expansion of stomatal openings and with the number of green leaves. Particularly important was the position on the stem where the lowest green leaf was attached. 2. Specific differences between the main culm and tillers in the ventilating pressure were discernible at the growth stages prior to heading, but they diminished towards maturity. 3. Seasonal changes in the ventilating pressure was recognized decidedly, the pressure being lowest at the stage of differentiation of ear-primordia. 4. Oxygen transference from the top to the roots might reasonably be affirmed.