Influence of Soil Moisture and Ambient Temperature on Yield and Quality of Alfalfa Forage¹

Abstract

Alfalfa grown at high soil moisture stress in growth chamber and field studies yielded less dry matter than that grown at low soil moisture stress. A higher percentage of leaves, higher percentage of in vitro digestibility (IVDDM), and lower percentages of acid detergent fiber (ADF) and lignin (ADL) often occurred in forage grown at high soil moisture stress. Soil moisture did not affect the percentage of crude protein (CP) consistently. Under controlled‐environment conditions, alfalfa grown at high temperatures (27 C day/21 C night) yielded less dry matter and had lower digestibility and higher ADF and ADL than that grown at lower temperatures (16 C day/10 C night). This occurred even though percentage of leaves and CP increased at high temperatures. The lowest ADF concentration (indicative of highest quality) occurred at low temperatures and high soil moisture stress; also, IVDDM was among its highest and ADL among its lowest levels under these conditions (also indicative of high quality). Low temperatures and low soil moisture stress were generally associated with a higher yield of a relatively higher quality forage than were high temperatures and high soil moisture stress. Crude protein failed to estimate alfalfa quality when forage was produced in diverse climates, confirming earlier reports.

Quality and morphological characteristics of alfalfa as affected by soil moisture, pH and phosphorus fertilization

“…2) and ADL (Fig. 3) appeared to be higher in alfalfa grown under warm compared to cold temperatures which is in agreement with the results of Vough and Marten (1971). The decreased ADF content due to cold temperature could be important in animal production since there is a negative relationship between fiber content and DM intake (Seoane 1982).…”

“…The decreased ADF content due to cold temperature could be important in animal production since there is a negative relationship between fiber content and DM intake (Seoane 1982). High temperature increases CP content due to increased leafprotein and higher leaf percentage (Vough and Marten 1971 (35'C) is associated with lower number of (Lee and Smith 1972). Smith (1969) (Nuttall 1976 Ste-Rosalie (Fig.…”

Russian wildrye nutritive quality as affected by accession and environment

“…In other studies, water-stressed tropical grass (Panicum maximum var. trichoglume) was lower in digestibility (Wilson and Ng 1975), while water-stressed alfalfa (Medicago sativa L.) often was higher in IVDMD (Vough and Marten 1971). It seems clear that water stress on plants at Mandan and Swift Current, in year 2, could have had an affect on forage quality, but the direction of that effect is not clear.…”

Water-stress effects on forage quality of alfalfa

“…Most previous work on effects of water stress on forage quality of alfalfa has focused on crude-protein concentra tion and dry-matter digestibility (e.g., Gifford andJensen, 1967J Vough andMarten, 1971;Snaydon, 1972b;Carter and Sheaffer, 1983a). Although cell-wall concentration and cell-2 wall composition (proportion of lignin, cellulose, and hemicellulose) are important characteristics affecting forage quality (Van Soest, 1983), little is known of their responses to water stress.…”

“…Although cell-wall concentration and cell-2 wall composition (proportion of lignin, cellulose, and hemicellulose) are important characteristics affecting forage quality (Van Soest, 1983), little is known of their responses to water stress. In addition, results on the effects of water stress on protein concentration have been conflicting; some workers reported inconsistent effects (Snaydon, 1972b;Vough and Marten, 1971;Carter and Sheaffer, 1983a), while others reported increased protein concentration under water stress (Gifford and Jensen, 1967;Walgenbach et al, 1981). Clearly, additional study is needed to resolve these discrepancies as well as to fill in gaps in existing knowledge.…”