熱帶條件下多年生黑麥草水分脅迫閾值及Ks系數(shù)評估

Pessl植物生理生態(tài)系統(tǒng)：熱帶條件下多年生黑麥草水分脅迫閾值及Ks系數(shù)評估

Pessl植物生理生態(tài)監(jiān)測系統(tǒng)的全套監(jiān)測系統(tǒng)和在線平臺FieldClimate適用于所有氣候區(qū)，可用于各種行業(yè)和各種用途——從農(nóng)業(yè)到研究、水文、氣象、洪水警報等。iMetos植物生理生態(tài)監(jiān)測系統(tǒng)已經(jīng)成為一個全球品牌，使用持續(xù)時間更長，性能更好，是通用的天氣監(jiān)測設(shè)備，具有早期識別和警報功能（有SMS手機提醒功能）；可以用來計劃、控制和管理復(fù)雜的獨立氣象過程。該監(jiān)測系統(tǒng)專為不同氣候區(qū)域的多種任務(wù)而設(shè)計。其可以安裝多達(dá)600個傳感器，如土壤和空氣濕度、溫度、降雨、風(fēng)速、風(fēng)向、葉片 濕度、總體輻射等傳感器。

摘要：多年生黑麥草(Lolium perenne) 是哥倫比亞赤道高地地區(qū)的主要牧草作物，因為它具有很高的營養(yǎng)價值和生產(chǎn)牛奶和肉。本研究旨在確定可用土壤水分的相對消耗與多年生黑麥草冠層擴張和關(guān)閉氣孔的Ks值之間的關(guān)系，并確定水分脅迫的閾值。實驗在受控環(huán)境條件下的盆中進行。這些花盆以完全隨機的方式排列。該實驗包括五種處理——包括對照處理——土壤水分虧缺的處理，隨著作物周期的發(fā)展，這些處理逐漸增加了枯竭水平。這產(chǎn)生了一個生長階段的各種條件。對于每個處理，進行四次重復(fù) 生物質(zhì)生產(chǎn)受到水分脅迫的顯著影響。結(jié)果表明，Ks 的上限和下限分別為冠層擴張（CE）的土壤中總有效水（TAW）耗竭水平（p）的 0.28 和 1.3，以及 0.25 和 1.1p TAW 氣孔關(guān)閉 (gs)。二次函數(shù)適用于 CE (R2 = 0.72) 和 CS (R2 = 0.73)；此外，具有正形狀因子（sf）的FAO-AquaCrop的Ks函數(shù)如下：sf = 11，CE為0.22，sf = 4.3，gs為RMSE 0.19。我們的研究結(jié)果表明，黑麥草對水分脅迫具有中等敏感性。糧農(nóng)組織的 Ks 函數(shù)與實驗數(shù)據(jù)之間發(fā)現(xiàn)的差異要求使用模型，并根據(jù)每個案例調(diào)整參數(shù)。

試驗期間不同處理的土壤體積含水量(%) 與種植后天數(shù)的關(guān)系
 

Water Stress Thresholds and Evaluation of Coefficient Ks for Perennial Ryegrass in Tropical Conditions

Abstract: Perennial ryegrass (Lolium perenne) is the predominant forage crop in the equatorial highland zones of Colombia due to its high nutritional value and versatility to produce both milk and meat. This study aimed to determine the relationship between the relative depletion of usable soil water and the Ks values of canopy expansion and closure stomatal of perennial ryegrass, as well as to identify the threshold values of water stress. The experiment was carried out in pots under a controlled environment condition. These pots were arranged in a completely randomized manner. The experiment consisted of five treatments—including control treatment—of water deficits in the soil that progressively increased the depletion level as the crop cycle developed. This generated a wide range of conditions in the growth stages. For each treatment, four repetitions were performed Biomass production was significantly affected by water stress. The results show that the upper and lower thresholds of Ks were 0.28 and 1.3 of the depletion level (p) of the total available water (TAW) in the soil for the expansion of the canopy (CE), and 0.25 and 1.1 p of the TAW for stomatal closure (gs). Quadratic functions were fitted for both the CE (R2 = 0.72) and CS (R2 = 0.73); moreover, the

Ks function of FAO-AquaCrop with positive shape factor (sf) was as follows: sf = 11, RMSE 0.22 for CE, and sf = 4.3, RMSE 0.19 for gs. Our results indicate that ryegrass is moderately sensitive to water stress. The differences found between the Ks function of FAO and the experimental data call for the need to use modeling with parameters adapted for each case.