因應氣候變化下西南沿海農業區的耕作模式設計

Cropping pattern design in southwestern coastal agricultural areas in response to climate change

江志峯(Chih-Feng Chiang)

輪作系統 ； 作物型態 ； 農地資源管理 ； 作物接替 ； Rotation system ； Cropping pattern ； Agricultural resources management ； Crop succession

臺中區農業改良場特刊

151號（2023 / 10 / 01）

142 - 160

繁體中文;英文

設計新的耕作制度並實質進行大面積驗證，以（1）篩選合適作物或品種、耕種方法、耕犁方式等，並評估現有環境特性，調整目前的耕作制度，以因應暴雨、長乾旱、高熱出現頻繁的氣候，求得最適佈置及較高收益；（2）推廣新的耕作制度，有效利用農業資源，提高此地區產業價值。2018-2021年於中部沿海低生產力地區建構一年三季水旱輪作制度與最少使用化學資材的耕作制度，主要栽培作物的模式為春作不整地旱作（玉米）－雨季直播水稻-秋作不整地旱作（大豆）的方式一年三作的節約資源型的耕作系統；配合本區域旱澇季明顯的氣候型態及作物的需水與耐旱特性，實施以二期作（雨季）直播水稻為主，每年輪換作物方式進行。作物栽培原則選擇以互補的可共享資源而不會導致後續作物的水與養分缺乏，提高水肥利用效率。需氮量高的作物可在固氮豆科作物之後（例如：大豆－玉米）。對需經耕犁的作物也應跟隨在不整地旱作物栽培後，強化深層土壤構造的保水力，可減少當季作物灌溉水量利於加深土壤有效供水深度（玉米－水稻）。當土壤肥力水平最低時，應在輪作結束時佈置土壤生產力低的作物，以利於繼承上季作物收穫後殘留的土壤水分（水稻－大豆）。現地進行結果顯示，保育耕犁春作玉米或毛豆－二期作直播水稻及不整地秋作大豆－食用玉米或小麥等作物的行播種植之新耕作模式，除可增加30%農田產能外，相對兩期作水稻季提高51-121%的總粗收益。

A land stability validation of a new cultivation system designed for single-phase field water supply area is conducted to promote new cropping model upgrading production value by efficient use of agro-ecological resources and better selection of crops, cultivars, cultivation methods and tillage for the design of new cropping system with best income (compared to existing system). During 2018-2021, a rotation system of three-crops per year (spring non - tillage fresh use corn - direct seeded rice - autumn non - tillage soybean) combined with less chemical material input are introduced in Southwestern coastal agricultural areas of poor productivity. The benefits observed from rotation among mutual complementary (paddy-upland) crops are co-sharing resources greatly enhance water/nutrient use and avoid water/nutrient efficiency of neighboring or subsequent next crop. The cropping order arranged for high N requirement crop can be after previous N-fixing legumes (soybean-corn), and that of tillage requiring crop can be after previous non-tillage upland crop (corn-paddy), which would strengthen water retention capacity of deep layer soil structure, reducing irrigation demand of current crop and hence, increasing soil available (supplying) water depth (corn-paddy). After a rotation cycle, when soil fertility at least level. Low fertility required crop should be select to plant for inheriting uptake of remaining residue soil moisture of last crops. The new cultivation models of conservation tillage of spring corn or soybean- 2nd direct seeded rice and autumn non-tillage soybean-- fresh use corn/wheat (row planting) have resulted in not only increasing field productivity potential up to 30% but upgrade gross income 51~121% of two crops of rice.