我國農地需求推估之研究

Abstract

2006年至2008年世界糧食供需失衡，糧食價格巨幅上漲，導致全球糧食危機。經濟合作暨發展組織(OECD)與聯合國世界糧農組織(FAO)推估未來十年世界糧食價格仍將處於高價位，糧食安全問題受到重視。我國為糧食淨進口國，糧食自給率偏低，以熱量計算之2011年糧食自給率為33.5%，相較日本、韓國等先進國家為低。我國大部分糧食供給依賴進口，當世界糧食價格巨幅上漲時，我國糧食安全將受到影響。為確保我國糧食安全，行政院農業委員會於2011年召開「全國糧食安全會議」，研擬糧食安全相關因應對策，包括我國應加強優良農地保護，以及保有一定面積之農地。當糧食完全無法進口時，我國是否有足夠的農地資源來生產及提供國人足夠的糧食，以維持國人基本效用、健康與營養所需，成為值得探討之重要議題。因此，林國慶(2011)即針對我國若於2020年發生非常時期狀況，完全無法進口糧食時，我國是否能利用當時的農地資源，提供國人基本糧食需求，包括效用、健康與營養之考量(包含避免基本消費型態顯著改變，提供平均每人每日2,000大卡消費熱量，以及蛋白質消費熱量占總消費熱量比例至少12%)進行研究。根據其研究成果，當我國於2020年發生非常時期，且完全無法進口糧食時，我國約需要74.00萬公頃農地，才能維持國人基本健康與營養。 林國慶(2011)之非常時期農地推估，為完全無法進口之情況，但是實際上，當糧食進口量減少至一定比例時，國內糧食供給就會受到顯著影響。因此，本研究將林國慶(2011)之數學規劃模型進行修改，進一步將不同進口量設定為不同時期，包括平常時期與非常時期。平常時期定義為當2020年之糧食進口量受到限制時，進口量為2011年進口量的50%以上(不包含50%)之情形，包含100%可以進口之情況。非常時期則定義為2020年的糧食進口量受到嚴重影響，進口量為2011年進口量的50%以下(包含50%)之情形，包含完全無法進口。在不同時期之不同情境下，本研究推估我國至少需要多少農地，以提供國人符合基本效用、健康與營養需求之糧食。 研究結果顯示，我國若於2020年，在糧食可完全進口的情況下，為避免國人消費型態受到顯著改變，我國至少需要之農地面積為60.22萬公頃，為目前我國80.83萬公頃農地面積的74.50%；我國若於2020年，當進口量受到限制，降為2011年進口量之90%、80%、70%、60%以及50%時，分別需要69.03萬公頃、78.64萬公頃、91.71萬公頃、107.63萬公頃以及120.48萬公頃之農地生產糧食，以維持我國近年消費型態。由此可知，當糧食進口量降至2011年進口量之75%以下時，我國將無法利用現有的農地生產糧食，以維持我國近年的消費型態。 我國若於2020年發生非常時期，在完全無法進口之情況下，為維持國人基本健康與營養，我國至少需要75.05萬公頃之農地生產糧食。我國若於2020年發生非常時期，糧食進口受到嚴重限制與影響下，考慮進口量降至2011年進口量之10%、20%、30%、40%以及50%情況下，為達到我國國人基本健康與營養，我國需要農地面積分別為61.11萬公頃、49.52萬公頃、39.76萬公頃、30.05萬公頃以及22.92萬公頃。我國2020年發生非常時期時，若無法進口期間為一年以內之情況下，且考慮存在稻米與蔬菜庫存，為達到我國國人基本健康與營養，我國至少需要69.72萬公頃之農地。若將庫存制度擴充至大豆、小麥與玉米，則我國至少需要55.51萬公頃之農地。由此可知，在糧食庫存制度下，我國所需農地面積將可顯著降低，糧食安全水準將會提升。 本研究政策建議如下:(1)我國未來至少需要保留75萬至78萬公頃農地生產糧食，以確保糧食安全以及避免糧食消費效用受到顯著影響；(2)當糧食進口量低於2011年進口量之75%時，為避免國人消費型態受到顯著影響，我國應建立相關應變制度與措施；(3)為確保糧食安全，我國應建立大豆、小麥與玉米相關儲備體系。

Due to the unbalanced global food supply and demand in the period of 2006 to 2008, the world food prices have increased significantly and caused global food crisis. Based on the forecast report from Food and Agriculture Organization of the United Nations (FAO) and Organization for Economic Co-operation and Development (OECD),these high food prices level will stay for at least another decade. The food security issue has attracted worldwide attention. Taiwan is one of the important net food-importing countries with a low food self-sufficiency rate, on a calorie basis only 33.5% in 2011, which was lower than the developed countries, such as Japan and Korea. Since most of the food supply in Taiwan depends on imports, when the world food prices increased significantly, the food security will be affected. In order to strengthen the national food security, the Council of Agriculture held ‘National Food Security Conference’ in 2011 to consolidate the ideas and formulate the countermeasures. Among them includes strengthening efforts to preserve prime agricultural land and maintaining certain amount of agricultural land. One of the important issues is that whether Taiwan has enough agricultural land resources to produce enough food to fulfill the needs of people, including the basic utility, healthy and nutrient requirements, if Taiwan could not import food during the emergency period. Lin (2011) studied the scenario that if the emergency period occurred in 2020 and Taiwan could not import food, whether by that time Taiwan would have enough agricultural land resources to produce enough food to support the needs of the people, including the basic utility, healthy and nutrient needs (including avoiding the significant changes of the basic consumption patterns, the minimum calorie intake of 2,000 Kcal per person per day and the minimum protein calorie ratio of 12%). Based on the study results, if the emergency period occurs in 2020 and Taiwan could not import food, Taiwan would need to have at least 740 thousand hectares of agricultural land to support the basic healthy and nutrient needs of the people. Lin’s agricultural land estimation was conducted under the emergency period without food imports, however in reality when the food imports are decreased to a certain extent, the domestic food supply situation might have already been significantly affected. This study modifies Lin’s mathematical programming model and makes estimation under different level of food imports under normal period and emergency period situation. The normal period is defined as a period whereby the food import volume becomes 50 to 100% of the level in 2011. On the other hand, the emergency period is a period with import volume severely affected and becomes 50% or less than the level in 2011. Under the different assumed scenarios the objective of this study is to estimate the minimum amount of agricultural land required to fulfill the basic food needs of the Taiwanese people, including the consideration of the basic consumption patterns, healthy and nutrient needs. The results of the study showed that in the normal period, when the imports are not affected, 602,200 hectares of farmland is needed without significant changes of domestic people’s basic consumption patterns. In addition, if the food imports are limited to 90%, 80%, 70%, 60% and 50% of the level in 2011, the minimum amount of agricultural land needed is 690, 780, 917, 1076 and 1204 thousands hectares respectively. This would imply that if the food imports fell to 75% or less of the level in 2011, Taiwan will not be able to use the existing agricultural land to produce enough food to fulfill the need of the people without significantly affecting the food consumption pattern. In an emergency period without any food imports, in order to maintain domestic people’s basic healthy and nutrient needs, the minimum amount of 750,500 hectares of farmland is needed. If the food imports are severely affected and decrease to 0%, 10%, 20%, 30%, 40% and 50% of the level in 2011, the minimum amount of 750, 611, 495, 397, 300 and 229 hectares of farmland are needed respectively. Taking into the consideration of the existence of rice and vegetable stocks, and with the emergency period less than a year without any food imports, in order to maintain the basic food needs Taiwan needs at least 697,200 hectares of agricultural land. If the reserve system were expanded to soybeans, wheat and maize, at least 555,100 hectares of agricultural land are needed. With the food reserve system, the minimum amount of agricultural land required could be therefore significantly reduced and the food safety level enhanced. Based on the study results, the policy recommendations are as follows:(1)In order to achieve food security objective, the minimum amount of agricultural land needed is 750 to 780 thousands hectares；(2)If the food import level has fallen to 75% of the level in 2011, the consumption pattern will be significantly affected, the government should formulate some measure to reduce the adverse impacts；(3)The food reserve system should be expanded to include soybeans, wheat and maize to enhance national food security.