頁籤選單縮合
| 題 名 | 紅壤鳳梨鉀肥施用法及磷鎂素肥效試驗=Response of Pineapple on a Latosol to Phosphorus, Magnesium and Differently Applied Potassium |
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| 作 者 | 吳水欽; 蘇楠榮; | 書刊名 | 中華農學會報 |
| 卷 期 | 49 民54.03 |
| 頁 次 | 頁48-64 |
| 關鍵詞 | 紅壤; 鳳梨; 鉀肥; 磷鎂素肥; |
| 語 文 | 中文(Chinese) |
| 中文摘要 | 老埤紅壤缺乏鉀素而鳳梨施鉀有效之事實，前此已有證明；早年粗放試驗亦表示該地施用磷肥對鳳梨增產有效；同時化學分析表示該地土壤含鎂量在本省鳳梨土壤中屬最缺乏之一。為確定該土壤施用磷肥之效果，探明鉀肥可否以基肥全量施下以節省工資，磷鉀之連應情形以及鎂肥有無真正增產效果等，特於民國50年秋舉辦此項試驗。 (一)本試驗以有磷(P)與無磷(P0)等二種磷肥處理，及無鉀(K0)，鉀以基肥施用(Kb)，鉀以追肥分6次施用(Ks) 等三種鉀肥處理，互相組合排成拉丁方設計，並各小區再分為兩副區，配以無鎂(Mg0)與有鎂(Mg)兩種鎂肥處理，每副區試驗株數80株。主作期要素用量為每株N 15克，P2O5 5克，K2O 15克，MgO 3克。所用肥料為尿素，過磷酸鈣，硫酸鉀及工業用硫酸鎂。 (二)據生育調查結果，磷肥及鉀肥對葉長、葉幅及葉數之效果均頗為顯著。對葉長及葉幅之效果在初期及中期(5月~9月)已頗明顯，但對葉數之影響係至末期(12月)始達頗顯著之程度。鉀肥以基肥施用時，初期(5月)發育顯較鉀肥分屍時為佳，但至中期(9月)後者之葉幅已超過前者，而至末期則鉀肥分施區之葉長葉幅均超過鉀肥以基肥施用者，顯示種植前多量施用之鉀肥已逐漸消耗，致對後期生長已無貢獻。鎂肥(在生長中期施用)對生長之影響不明顯，惟對後期葉幅似稍有增大之效果。 (三)對平均果重增加之效果，磷肥達5%顯著標準，鉀肥達1%顯著標準。對公頃總產量之增加，磷肥之效果未達顯著程度，鉀肥之效果達5%顯著標準。但無論對平均果重或公頃總產量之增加，鉀肥均在分施時效果大，全部當基肥時則較小。 (四)又鉀肥對果重及產量之效果，在不施磷時較大，施磷時變小；磷肥效果，在不施鉀時及鉀以基肥施用時較大，鉀分施時則變為甚小。換言之，磷肥及鉀肥之間有互相削減對方之效果之現象，亦?表示此兩種肥料可互相代替對方肥料之缺乏(至少至某一程度)，因而已施一素時他素之效果降低。此種現象與Liebig 最小養分率恰為相反，似可以下面三種假設加以解釋： 1. 過磷酸鈣之Ca與硫酸鉀之K，有陽離子共同之效果。 2. 施磷可提高土壤鉀素之吸收量，施鉀亦可提高土壤磷素之吸收量，因而減少對肥料之需要量。 3. 作物有「徒長臨界點」(依條件而變)，磷肥對生長之效果加上鉀肥對生長之效果，已使生長量超過徒長臨界點，產量之增加已受到限制。 (五)鎂肥增加果重之效果，在夏果未達顯著之程度；但在秋果則變為顯著，幾乎達1%機率之顯著標準。此表示由土壤中供給之鎂素已隨生長期間之延長而愈趨缺乏。雖鎂肥對主作總產量之增產效果在統計上為未達顯著之程度，但以平均值而言每公頃可增產1.52公頃。實際上不施鉀時鎂肥效果較大，鉀分施時居中，鉀肥以基肥施用時無效。 (六)各處理夏果平均果重之大小，係受花芽分化期(12月)葉片長幅積之密切影響，後者愈大果重則愈大，在長幅積555 cm2 以下兩者間成直線關係；但在此點以上時雖長幅積增加，果重亦幾乎不增加。換言之，555 cm2為本試驗區之徒長臨界點，其主要限制因素似為結實期間之極端乾旱。 (七)不但磷鉀兩種肥料能增加夏果之肉柱聲果百分率，鎂肥亦可增加夏果肉柱聲果，三種肥料之效果均達統計學上頗顯著之標準。鉀肥分次施用時較以基肥施用時肉柱聲果為多。本年度肉柱聲果百分率頗低，不施磷、鉀、鎂區百分率14.3%，磷、鉀、鎂同施而鉀肥採用分施法時增至38.7%。 (八)根據經濟計算，利潤最高之處理為鉀肥分施而不施肥者，每公頃主作純利4,176元；鉀分施且施磷肥者次之，每公頃主作純利3,116元。由於後者產量僅高於前者少許，而純利短少一千多元，故雖老埤紅壤確有缺磷，但不應多施磷肥以免浪費(每株似可施2~3克)。鎂肥在該試驗區地點之效果仍不合算，但在該場其他地點有土壤含鎂量更低者，其施鎂效果必更大，同時今後栽培倘繼續不施鎂肥，必愈趨缺乏。 |
| 英文摘要 | A field experiment was conducted with pineapple on the latosol of Laopei Plantation for testing the effects of added phosphorus and magnesium, the comparative effects of basic and split applications of potassium and the interaction between phosphorus and potassium. The soil contained 81 ppm exchangeable K and 62 ppm exchangeable Mg. 1. In the trial two levels of P2O5, i.e., none (P0) and 5g per plant crop as basic dressing (P), were combined factorially with three potassium treatments, i.e., no potash (K0), 15g K2O per plant, applied in band under the plant as basic dressing (Kb) and 15g K2O per plant, split-applied in 6 doses as top dressings (Ks), and layed out in a Latin square design. Each plot was split into two subplots which received no magnesium (Mg0) and 3g MgO per plant (Mg), respectively. Nitrogen was applied at a fixed rate of 15g per plant per crop. The fertilizers used were urea, calcium superphosphate, potassium sulfate and magnesium sulfate. The size of subplot was 6m×3m, with a plant number of 80. 2. According to the results of growth measurements, the effects of superphosphate and potassium sulfate on the increases of length, width and number of leaves were highly significant. Their effects on the leaf length and width were already marked at the early and middle stages of growth (May to September), although the increases in leaf count due to applied phosphate and potash reached the highly significant level only in the later stage (December). 3. When all potash was applied as basic dressing (Kb) the growth of pineapple in the early stage (May) was significantly better than when it was split-applied (Ks). In the middle stage (September), however, the leaf width and length were significantly in favor of the Ks treatment. This indicates that the potassium applied at planting time a large dose had been consumed gradually and could not last so long as to ensure the normal growth in the later stage. 4. Magnesium sulfate had no consistent effect on the growth of pineapple. In the later stage, however, it seems to have increased the leaf width slightly. 5. The effects of phosphate and potash in increasing the mean fruit weight were significant and highly significant, respectively. So far as the hectare yield is concerned, the effect of phosphate did not attain the statistical significance, while that of potash was significant at the 5% level. For both the mean fruit weight and the hectare yield, potash was more effective when applied in 6 doses than when applied in one dose as the basic dressing. 6. The effect of potash was higher in the absence of applied phosphate than in its presence. The effect of phosphate was higher where no potash was applied and where the potash was used as basic dressing, but become very low where potash was split-applied. In other words, the potash and phosphate mutually decreased the effect of each other. This also denotes that the two fertilizers can mutually satisfy their individual deficiencies, at least to some extent, and the application of either one results in the lowered requirement for the other. The phenomenon is the reverse of Liebig's Law of Minimum and may be explained by the following assumptions: 1) The Ca ions of superphosphate and the K ions of potassium sulfate have common effect of cations. 2) The application of phosphorus can improve the uptake of soil potassium, while the application of potassium can improve the uptake of soil phosphorus, thus resulting in the lowered requirement for the fertilizer potassium and phosphorus. 3) Crops have "Critical growth level", which varies with changes in the condition. The cumulative effects of the two fertilizers resulted in a growth exceeding this " Critical growth level", and, of necessity, the yields increment was restricted. 7. Though the increase in fruit weight due to the application of magnesium was not significant in the case of summer fruit, it almost reached the 1% level significance in the case of autumn fruit. This shows that the soil supply of magnesium became increasingly deficient with the lapse of growth period. The effect of magnesium on the total hectare yield of plant crop was not significant statistically. Nevertheless, the tendency of yield increase was rather definite. Though the average yield increment was 1.52 tons per ha., the increment was large (1.99-3.54 tons) in the absence of applied potash, medium (1.47-1.58 tons) when potash was added in split doses and negligible (0.23-0.31 tons) when potash was applied as basic dressing. 8. The mean weights of summer fruits for the 12 treatment combinations were intimately affected by the " leaf size index" (maximum length × maximum width) of the pineapple plant at the stage of floral initiation (December). The larger the "leaf size index", the larger the fruit weight. The relation was linear below the index value of 555 cm2. Above this level the further increase in growth was not accompanied by appreciable increase in the fruit weight. In other words, 555 cm2 was the "Critical growth level" for this experiment; the dominant limiting factor in this particular case appears to be the extreme drought during the fruiting stage. 9. The percentage "flesh-soung" fruits (the compact fruits which give a dull muscle-like sound on tapping with finger) was increased not only by phosphate and potash but also by magnesium, the effects of the three nutrients all attaining the 1% significance level. Within the potash treatments the split-application gave a higher percentage than the basic application. The percentage "flesh-sound" fruits this year was universally low, being 14.3% for P0K0Mg0 (the lowest) and 38.7% for PKsMg (the highest). 10. According to the economic appraisal of PK treatments, the highest net profit was obtained by the split application of without phosphate (NT$4,176 per ha), followed by the split application of potash with phosphate (NT$ 3,116 per ha). Since the yield in the latter case was only slightly higher than in the former, it is not worthwhile to apply so much phosphate as in this trial. It is regarded that 2-3g P2O5 per plant may be sufficient for maintaining an economical high yield level in this latosolic plantation. 11. The yield increase obtained by the addition of magnesium at the experimental site was not large enougn to be profitable. However, the effect must be larger in other parts of the same plantation and in other plantations where the magnesium content of soil had been found to be much lower than in the location of this trial. Even in the same plot, the deficiency will soon become pronounced unless magnesium is supplemented as a fertilizer. |
本系統中英文摘要資訊取自各篇刊載內容。