Alfalfa Dry Matter Yield Research Articles

Effect of Spacing of Elephant Grass Intercropping with Alfalfa on Biomass Yield and Nutritive Value of Elephant Grass in Fedis District, Eastern Ethiopia

The study was conducted by Fedis Agricultural Research Center (FARC) at Boko station in Fedis district. The experiment consisted of three different spacing arrangements: S1 (100 cm x 50 cm), S2 (75 cm x 50cm) and S3 (50 cm x 50 cm), and two cropping systems (intercrop and sole planting). These treatments were combined in a 3 x 2 factorial arrangement using a randomized complete block design with four replications. Forage samples were collected at ninety (90) days for elephant grass and 10% flowering for Alfalfa. The results showed that spacing and the interaction between spacing and intercropping had a significant (p<0.05) effect on herbage dry matter yield (DMY) and crude protein yield (CPY) of elephant grass. However, intercropping had no significant (p>0.05) effect on herbage DMY and CPY. Intercropping can increase the yield of herbage dry matter and total herbage dry matter when compared to pure stand elephant grass. The yield advantage can be up to 3.18% and 19.65%, respectively. Spacing does not significantly affect the dry matter yield of Alfalfa, but the cropping system does. Intercropping and narrow spacing resulted in higher total dry matter yield, due to the additive effect of intercropped Alfalfa dry matter yield. Among the three different spacing, the narrowest spacing S3 recorded the highest dry matter yield (25.62 t/ha), followed by S2 (22.28 t/ha) and S1 (18.33 t/ha). Spacing and intercropping have no significant effect on the chemical composition of elephant grass, but intercropping can increase the dry matter and decrease the ash content of elephant grass. Farmers in the study area and other regions with similar agro-ecology are advised to consider intercropping Alfalfa two weeks after establishing elephant grass. This should be done at an inter and intra-row spacing of 50 cm to achieve a higher herbage dry matter yield for both, elephant grass and total forage.

Effects of Fall Sowing Dates on Winter Survival and Dry Matter Yields of Alfalfa in the Central Area of South Korea

Effects of Fall Sowing Dates on Winter Survival and Dry Matter Yields of Alfalfa in the Central Area of South Korea

Effect of Sowing Date on Growth Characteristics and Dry Matter Yield of Alfalfa in a Dry Paddy Field

Effect of Sowing Date on Growth Characteristics and Dry Matter Yield of Alfalfa in a Dry Paddy Field

Yield and quality properties of alfalfa (Medicago sativa L.) and their influencing factors in China

Alfalfa (Medicago sativa L.) is the most valuable perennial forage crop, and assessing its yield and quality properties is essential to evaluate forage value of livestock production. However, regional patterns and controlling factors of the yield and quality of alfalfa have not been well documented. In this study, using a dataset of 7166 observations from 301 sites across the country collected from 334 publications, we explored the relationships between the yield and quality properties of alfalfa in China and the effects of environmental factors and management practices on them. The average dry matter yield of alfalfa was 11.18 ± 6.69 Mg ha-1, with average crude protein, ether extract, crude fiber, acid detergent fiber, neutral detergent fiber, crude ash, nitrogen-free extract, calcium, phosphorus and relative feed values of 19.05 ± 2.87%, 2.62 ± 0.97%, 27.16 ± 5.21%, 31.29 ± 5.58%, 40.48 ± 6.34%, 9.49 ± 1.59%, 38.67 ± 7.49%, 1.68 ± 0.55%, 0.25 ± 0.12%, and 151 ± 31.94, respectively. Alfalfa quality decreased with increasing yield. Geographically, alfalfa had higher yield and crude protein content in South China than in other regions. Quality was positively correlated with both precipitation and temperature, while yield showed a positive relationship with temperature but no significant relationship with precipitation. High soil nutrient availability (e. g., soil available nitrogen, SAN; soil available phosphorus, SAP; soil available potassium, SAK) improved the yield, while high SAN and SAP contents increased the crude protein content. The alfalfa yield increased and the quality decreased with advancing maturity and age, whereas increasing the number of harvests may benefit the quality. This study documents comprehensive information on the yield and quality of alfalfa and provides insights for policy makers for the effective management and sustainable development of alfalfa production.

Effect of Potassium Application Rate on Dry Matter Yield and Forage Nutritive Value in Alfalfa

The United States is the largest producer of alfalfa (Medicago sativa L.) however there is still a wide variation in yield among states. Potassium (K) is one of the key plant macronutrients that affect alfalfa yield and stand persistence. To the best of our knowledge, the evaluation of K rates on alfalfa forage yield and quality attributes has not been done in the United States. Thus, the main objective of this study was to evaluate the effect of K rates along with harvesting intervals (HI) and varieties on alfalfa dry matter yield (DMY), forage nutritive value, and soil K content. The experiment was carried out in a split-split plot with two HI (28 and 35-day after the first cut), two varieties (Hi–Gest 360: reduced-lignin and AFX 457: conventional), and four K application rates (0, 56, 112, and 168 kg K2O ha-1) in a randomized complete block with four replications. The results indicated that harvesting alfalfa at a shorter interval (28-day) resulted in higher dry matter yield and forage nutritive value than a longer harvest interval (35-day). Yield, nutritive values, and soil K content were, however, not significantly influenced by alfalfa variety and K rates. Further research is essential to quantify the actual trade-off between applied K and soil and plant K content in alfalfa production.

Effects of Nitrogen and Phosphorus Addition on Agronomic Characters, Photosynthetic Performance and Anatomical Structure of Alfalfa in Northern Xinjiang, China

The productivity of alfalfa is associated with a large amount of nitrogen (N) and phosphorus (P); the addition of exogenous N and P fertilizers can fully exploit the growth potential of alfalfa. However, there is uncertainty about the relationship between changes in alfalfa productivity and photosynthetic physiology and anatomy. We conducted field fertilization experiments on alfalfa in the second and third years under drip irrigation, as well as measurement of the photosynthetic physiology, anatomical structure and agronomic traits of alfalfa at different levels of N (0, 120 kg·ha−1) and different levels of P2O5 (0, 50, 100 and 150 kg·ha−1). The results showed that the dry matter yield (DMY), crude protein (CP), net photosynthetic rate (Pn) and specific leaf weight (SLW) were increased by 2.10~11.82%, 4.95~11.93%, 4.71~7.59% and 2.02~7.12% in the N application treatment compared with the non-N application treatment, while the DMY, CP, Pn and SLW were increased by 3.19~17.46%, 1.99~8.42%, 6.15~24.95% and 2.16~11.90% in the P application treatment compared with the non-P application treatment. N and P increase the thickness of the spongy tissue (ST) of alfalfa, which will facilitate the entry and exit of gas and water, and will further affect the photosynthetic indexes, such as stomatal conductance (Gs) and transpiration rate (Tr), of alfalfa leaves. Increased palisade tissue (PT) thickness will also enhance the adaptability of plant leaves to strong sunlight, thereby increasing the maximum net photosynthetic rate (Pmax) and light saturation point (LSP). Fertilization treatment showed the highest utilization efficiency for low light and better adaptation to strong light, but the Rd decreased. The comprehensive scores of principal component analysis for anatomical structure, photosynthetic performance and agronomic traits were N1P2 > N0P2 > N1P3 > N1P1 > N0P3 > N0P1 > N1P0 > N0P0. Therefore, the application of N and P fertilizers contributed to the adaptive changes in alfalfa leaf anatomy and the improvement of photosynthetic capacity, which were beneficial to the improvement of alfalfa dry matter yield, growth traits and nutritional quality, with the most obvious improvement effect obtained with the application of 120 kg·ha−1 of N and 100 kg·ha−1 of P2O5.

Water–phosphorus coupling enhances fine root turnover and dry matter yield of alfalfa under drip irrigation

AbstractAlfalfa (Medicago sativa L.)is an important forage with high quality and fine root turnover rate (FRTR). Soil phosphorus (P) availability greatly influences dry matter yield (DMY) and persistence of alfalfa. However, the effects of water (Wa)–P coupling under drip irrigation conditions on alfalfa FRTR and DMY have been rarely studied. Therefore, a 2‐yr field experiment was established with three randomized complete blocks in Xinjiang, China, evaluating three irrigation amounts (5,250, 6,000, and 6,750 m3 ha−1, referred to as W1, W2, and W3, respectively) and four P application rates (0, 50, 100, and 150 kg ha−1, referred to as P0, P1, P2, and P3, respectively) in 2017 and 2018. The Wa–P interaction had a significant effect on alfalfa DMY (P < .05), and DMY reached the maximum at W2P2 treatment. Fine root biomass (FRB) presented a bimodal pattern over time (on 21 June and 20 August) and mainly existed in the soil layers 20‒40 cm underground. All root variables including FRB were positively correlated with alfalfa DMY. Comprehensive analysis showed that W2P2 was the optimal treatment of the 12 treatments. Therefore, the irrigation amount of 6,000 m3 ha−1 and P application rate of 100 kg ha−1 seems beneficial to achieve the relatively rational FRTR and the greater DMY of alfalfa.

Effects of harvest intervals and seeding rates on dry matter yield and nutritive value of alfalfa cultivars.

Maturation process of alfalfa (Medicago sativa L.) could be prevented by the reduction of lignin content in terms of conventional breeding or transgenic technology. Alfalfa could exhibit higher leaf/stem ratio, with a concern of yield loss. The objective of this study was to compare forage yield and nutritive value of low lignin alfalfa and two reference varieties subjecting to two harvest intervals and three seeding rates. The experimental design was a randomized complete block in a split-split plot arrangement with four replicates, where harvest intervals (28-day and 35-day) were assigned to whole plots, seeding rates were subplots, and varieties were sub-subplots. The weighted mean nutritive value was applied to two production years of 2016 and 2017. Hi-Gest 360 (low lignin alfalfa) provided similar yield potential and increased nutritive value compared to two reference varieties. Over a two-year production period, alfalfa harvested at every 28-day interval provided more economic returns than those at 35-day interval. For the seeding year and first production year, five cuts made by the 28-day interval produced more yield than four cuts by the 35-day interval. Due to limited rainfall in May 2017, a sharp drop of the first cutting overturned the advantage of the five-cut system. Shorter intervals between harvests generally increased crude protein (CP) concentrations. The differences of relative feed value (RFV) between two harvest intervals tended to be great during the first and second cuttings. Overall, harvest interval had a large effect on nutritive value and a more significant effect on alfalfa dry matter yield than variety selection. Seeding rate did not affect alfalfa yield and nutritive value.

Differential survival of alfalfa varieties interseeded into corn silage

AbstractInterseeding alfalfa (Medicago sativa L.) into silage corn (Zea mays L.) can improve forage yield, farm profitability, and soil conservation, but unreliable alfalfa establishment hampers on‐farm adoption. This study evaluated seedling survival and growth of 36 alfalfa varieties differing in reported plant traits when interseeded at two Wisconsin sites in 2015 and at single sites in Wisconsin, Michigan, and Pennsylvania in 2016. Subplots of alfalfa varieties were sprayed with prohexadione‐calcium (PHD) at 0 or 0.42 kg acid equivalent (a.e.) ha–1 to assess changes in seedling survival mediated by this growth retardant. After corn harvest in 2015, average stand density of varieties in Wisconsin ranged from 15 to 94 plants m–2 without PHD and from 52 to 199 plants m–2 with PHD. Stand density largely determined subsequent first‐cut alfalfa dry matter yield, which ranged from 1.1 to 6.3 Mg ha–1. After corn harvest in 2016, stand density of varieties averaged across PHD treatments ranged from 113 to 248 plants m–2 in Michigan and Pennsylvania, compared with only 0.5 to 26 plants m–2 in Wisconsin; PHD treatment improved stand density only in Wisconsin but could not ensure adequate establishment under wet conditions that favored vigorous corn growth and foliar disease on alfalfa. Overall, establishment was poorly related to measured or reported alfalfa traits, but ‘55H94’ and hybrids were consistently among the best performing cultivars. Further work is needed to understand seedling survival mechanisms and to develop improved germplasm and production practices to ensure reliable establishment of interseeded alfalfa.

English

Alfalfa is an important legume forage with high nutritional quality. Harvest stage has an essential impact on alfalfa hay yield and nutritional quality. However, there is no clear indication about the effects of harvest time on the production performance, overwintering rate and economic benefits of alfalfa under drip irrigation. Therefore, this study was conducted to evaluate the impact of harvesting at bud stage (FB), 5% flowering stage (F5%), 15% flowering stage (F15%), and full bloom stage (F50%) on hay yield and quality, and economic benefits of two alfalfa cultivars i.e.,WL354HQ and Magnum551. Harvesting time had significant effect on hay yield of both cultivars (P ≤0.05) and the order of total dry matter yield (TDMY)was: F5%> F15%> F50%> FB. The alfalfa crude protein (CP)content of each cutting in alfalfa decreased gradually with the advance of the harvest stage, while the neutral detergent fiber (NDF)and acid detergent fiber (ADF)contents gradually increased. A comprehensive analysis of alfalfa dry matter yield(DMY), quality and overwintering rate was used to analyze the fuzzy similarity priority ratio, and the priority ranking was as follows: FB> F5%> F15%> F50%.Maximum economic benefits of both alfalfa cultivars were obtained atF5%harvest time, reaching 2703$ha-1 (WL354HQ) and 2585 $ha-1(Magnum551), followed by FB, F15%, and F50%. Therefore, in order to get more hay yield and economic returns, harvesting at 5% flowering stage of alfalfa seemed viable option under drip irrigation.© 2021 Friends Science Publishers

Improved Alfalfa Phosphate Utilization Using Zeolite Amendments in Low pH Soil

Soil amendments are used to increase the solubility of phosphate rocks (PRs) such that they can supply phosphorus (P) to high P-demanding crops. Zeolites are naturally occurring aluminosilicate minerals that can solubilize PRs and increase P nutrient supply. This study sought to evaluate the effects of zeolite addition in PR mixtures in dry matter yield (DMY), nutrient accumulation, and alfalfa’s agronomic efficiency. The experiment was conducted in a greenhouse where treatments comprised of two zeolites types (clinoptilolite and stilbite), three P sources (triple superphosphate-TSP, Morocco PR, and Cajati PR), five P levels (0, 22, 44, 87, and 131 mg kg−1), and five zeolites ratios (w/w) based on P2O5 levels (0, 25, 50, 100, and 200%). Eleven cuts of alfalfa were taken to quantify DMY and P accumulation. Alfalfa dry matter yield and P accumulation increased due to P fertilization. Reactive PR (Morocco) was more effective than TSP to increase alfalfa DMY and P accumulation. Phosphorus levels in soil did not increase with reactive PR (Morocco) fertilization and zeolite amendment. Zeolite stilbite just increased P solubilization and accumulation by alfalfa plants in a 150–200% ratio (zeolite/PR) with the low-reactive PR (Cajati). Under this experiment’s conditions, zeolite was not an efficient amendment combined with P soluble and reactive PR sources to increase alfalfa DM yield and P accumulation. Large amounts of zeolite were necessary to provide the low-efficiency PR source solubilization to satiate alfalfa P demand.

Influence of irrigation regimes on alfalfa dry matter yield and water productivity in a semiarid subtropical environment*

AbstractManaging water in alfalfa (Medicago sativa L.) production is crucial for sustaining the limited surface and groundwater resources. A 3‐year study in eastern New Mexico, USA, compared nine irrigation strategies that included various combinations of in‐season irrigations for six harvests (1–2–3–4–5–6, 1–2–3–4–5, 1–2–3–5, 1–2–3, 2–3–5, 1–2–5, 1–5, and 2–3) plus unirrigated control (none) to evaluate the dry matter (DM) yield production capability and irrigation efficiency. The number in each treatment structure represents irrigation provided for each cutting. For example, number ‘1’ represents irrigation provided for the first cutting; number ‘2’ represents irrigation provided for the second cutting, and so on. The results suggested that terminating irrigation for the last harvest (1–2–3–4–5), equivalent to 96 mm water saving, had no significant negative impact on annual DM yield of established alfalfa compared to season‐long full irrigation (1–2–3–4–5–6) (14.4 vs 13.3 t ha−1; P > 0.05) during the 3‐year study period. Irrigation water productivity was doubled when alfalfa was irrigated during the first three harvests (1–2–3), compared to 1–2–3–4–5–6 (0.050 vs 0.027 t ha−1 mm−1). The second and third harvests provided the greatest DM yields in alfalfa. The DM yields declined drastically after the third harvest, with the exception of the third year. Therefore, irrigating alfalfa early in the season during the initial three harvests is an important strategy when water is limited.

Nutritive Value of Alfalfa Harvested with a Modified Flail Chopper

The leaves of alfalfa (Medicago sativa L.) are a valuable source of protein, and the stems a source of fiber. Harvest methods are sought that would allow separation of different plant fractions for agricultural or industrial functions. A solution is proposed, consisting of collecting leaves together with upper, fine stem fragments, while leaving most of the stem standing in the field. For this purpose, a modified flail chopper (MFC), typically used for harvesting green forage, was employed. The objective of this study was to assess the forage value of alfalfa biomass harvested at various development stages using an MFC, and stem stubble remaining after harvest. Alfalfa was harvested with a sickle-bar mower or MFC in the first and second cuts at bud, early flower and late flower stages of development. Using the MFC, 60% to 74% of the potential dry matter yield of alfalfa was harvested, in which the proportion of leaves was, on average, 22% greater than the proportion of leaves in forage harvested with a mower. Crude protein concentration was, on average, 16% greater and neutral detergent fiber concentration 13% less in alfalfa harvested with the MFC than with a mower. In alfalfa harvested with the MFC at early flower, crude protein concentration and in vitro true digestibility were similar or greater than, with neutral and acid detergent fiber at a similar or lower level as in forage harvested with a mower at bud stage. The forage nutritive value of alfalfa harvested with an MFC at late flower was similar to the forage value of alfalfa cut with a mower at early flower. The chemical composition of the 20 to 50 cm tall residual stubble was affected little by plant maturity or harvest method, and the quality parameters also indicate the possibility of its forage use.

Uticaj faze košenja i setvene norme na prinos i kvalitet lucerke

Cultivated alfalfa (Medicago sativa L.) is a highly productive forage crop with great economic potential. Our objectives were to investigate the effects and interactions of environment, harvest maturity stage, seeding rate and cultivars on alfalfa dry matter yield and quality. The field experiment was carried out over 2010-2012 at the Experimental Field of Institute of Field and Vegetable Crops in Novi Sad, at two locations: (I) Cenej, and (II) Rimski Sancevi, which were characterized by a contrasting soil condition. The experimental treatments included two seeding rates of 8 and 16 kg ha-1, three different harvest maturity stages of alfalfa, and four alfalfa cultivars included as a subplot in every treatment. Harvesting alfalfa five times within a year (cutting in the beginning of flowering) in the second and third year of stand life is the most efficient harvest regime that allows full exploitation of cultivar genetic potential and environmental conditions. There was no difference in yields between harvests at early and full flowering stage (15.9 t ha-1). Data related to forage quality components show increase of nutritive value when harvesting alfalfa in earlier maturity stage. Maturity stage in the moment of harvesting significantly affected all quality parameters. The results obtained suggest that in a temperate climate of Southeast Europe there is little justification for planting higher seeding rates of alfalfa varieties under good establishment practices. Increasing seeding rates above 16 kg ha-1 does not provide a long-term boon in alfalfa production.

Prohexadione‐Calcium Rate and Timing Effects on Alfalfa Interseeded into Silage Corn

Core Ideas Higher prohexadione rates of 0.5 to 1 kg a.i. ha–1 enhanced interseeded alfalfa establishment and yield under stressful establishment conditions.Prohexadione application to 15 vs. 25 cm tall alfalfa seedlings provided similar improvements in alfalfa stand density and yield.Interseeding alfalfa increased overall corn+alfalfa forage production by 12%. Prohexadione‐calcium (PHD) can enhance establishment of alfalfa (Medicago sativa L.) interseeded into silage corn (Zea mays L.), but optimal application rates and timing for this growth regulator are unknown. Two experiments examined how single or split applications of 0.25 to 1.0 kg a.i. ha−1 of PHD applied to 15 or 25 cm tall glyphosate‐resistant alfalfa seedlings influenced growth, stand density, and yield of alfalfa and corn compared to untreated controls. The PHD treatments reduced seedling top growth by 13 to 32% and increased stand density of alfalfa by 19 to 81% in three out of four locations and alfalfa dry matter yield by 4 to 23% in two out of four locations the following year. Alfalfa responses were not consistently influenced by the rate and timing of PHD application, but higher rates proved advantageous under conditions that impaired alfalfa seedling survival under corn. Application of PHD on alfalfa had little or no effect on corn heights and yields. Corn population and alfalfa seeding rates influenced corn silage yield and alfalfa stand counts in at least one location, but these factors had little effect on crop responses to PHD. Combined 2‐yr yields of corn followed by alfalfa were 12% greater for the interseeding system than for solo‐seeded corn followed by spring seeded alfalfa. Overall, a single application of 0.5 to 1.0 kg a.i. ha−1 of PHD on 15 to 25 cm tall alfalfa proved effective for improving stand density and occasionally first year yield of glyphosate‐resistant alfalfa.

Planting Alfalfa with Cover Crops on Forage Dry Matter Yield and Nutritive Values of Alfalfa

The objective of this study was to evaluate the effect of planting alfalfa (Medicago sativa L.) with- and without cover crops on forage dry matter yield and nutritive values of alfalfa in Kansas, USA. In the first production year 2014, dry matter yield of mono-culture alfalfa appears to be compatible or even higher than planting with certain species of winter annual forages as a cover crop. Alfalfa planted with a combination of four different multi-species winter annual forages such as oats (Avena sativa L.), oilseed radish (Raphanus sativus L.), annual ryegrass (Lolium multiflorumL.), and turnip (Brassica rapa L.) had the highest dry matter yield of alfalfa in 2014.Dry matter yield of alfalfa in 2nd production year 2015 was similar to alfalfa + oats and alfalfa + oats + oilseed radish + annual ryegrass + turnip or significantly higher than alfalfa planted with annual ryegrass, oilseed radish, and turnip together. Based on two year of data in 2014 and 2015, the highest alfalfa yield occurred when alfalfa was planted with a combination of oats, oilseed radish, annual ryegrass, and turnip. The lowest dry matter yield of alfalfa occurred when alfalfa was planted with annual ryegrass.No significant differences in crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) were found when comparing alfalfa monoculture with alfalfa + oats, alfalfa + oilseed radish, alfalfa + oats + oilseed radish + annual ryegrass + turnip, and alfalfa + turnip treatments. When considering both dry matter and nutritive values of alfalfa, planting alfalfa with cover crops appears to be compatible or better practice than planting alfalfa monoculture.

Spatial variability of soil properties and yield of a grazed alfalfa pasture in Brazil

Knowledge of the spatial variability of soil properties and of forage yield is needed for informed use of soil inputs such as variable rate technology (VRT) for lime and fertilizers. The objective of this research was to map and evaluate the spatial variability of soil properties, yield, lime and fertilizer needs and economic return of an alfalfa pasture. The study was conducted in a 5.3 ha irrigated alfalfa pasture in Sao Carlos, SP, Brazil that was directly grazed and intensively managed in a 270-paddock rotational system. Alfalfa shoot dry matter yield was evaluated before grazing. Soil samples were collected at 0–0.2 m depth, and each sample represented a group of 2 or 3 paddocks. Apparent soil electrical conductivity (ECa) was measured with a contact sensor. The cost of producing 1 ha of alfalfa was estimated from the amount of lime and fertilizer needed and was then used to estimate the total cost of production for the dairy system. The alfalfa dry matter yield was used to simulate the pasture stocking rate, milk yield, gross revenue and net profit. The spatial variability of soil properties and site-specific liming and fertilizer needs were modeled using semi-variograms with VESPER software, the soil fertility information and economic return were modeled with SPRING software. The results showed that geostatistics and GIS were effective tools for revealing soil and pasture spatial variability and supporting management strategies. Soil nutrients were used to classify the soil spatial distribution map and design site-specific lime and fertilizer application maps. Spatial variation in forage and spatial estimates of stocking and milk yield are adequate pasture management tools. Spatial analyses of needs, forage availability and economic return are management tools for avoiding economic problems, as well as potential environmental problems, caused by unbalanced nutrient supplies and over- or under-grazing.

Prohexadione–Calcium Improves Stand Density and Yield of Alfalfa Interseeded into Silage Corn

Interseeded alfalfa (Medicago sativa L.) could serve as a dual‐purpose crop to provide groundcover for silage corn (Zea mays L.) and forage during subsequent years of production, but interspecific competition often leads to poor stands of alfalfa and unsatisfactory yields of corn. Four experiments evaluated whether interspecific competition could be alleviated by application of plant growth retardants (PGRs) on alfalfa interseeded at corn planting. In three experiments, foliar application of prohexadione‐calcium (PHD) on seedlings approximately doubled stand density of interseeded alfalfa during establishment in corn and following 1 yr of alfalfa forage production. Untimely PHD application in one experiment, however, failed to prevent stand failure of alfalfa growing under warm and damp conditions that favored vigorous growth of corn. When successfully established without PHD, average dry matter yield (DMY) of interseeded alfalfa the year following corn was 85% greater than conventionally spring‐seeded alfalfa; prior year PHD application further increased DMY of interseeded alfalfa by 15%. When tested with PHD in two experiments, seed soaking or coating with uniconazole (UCZ) or paclobutrazol (PBZ) reduced stand density and had neutral or adverse impacts on DMY of alfalfa following corn. Interseeding reduced silage corn DMY by an average of 10% compared to monoculture corn and PGR treatment of alfalfa usually failed to alleviate yield depression in corn. Overall, PHD shows promise for enhancing the establishment and subsequent yield of interseeded alfalfa, but further work is needed to refine this production system for farm use.Core Ideas Interseeded alfalfa can serve as a cover and forage crop Interseeding alfalfa in corn can double first year yields of alfalfa Prohexadione doubles seedling survival of interseeded alfalfa Prohexadione increases first year yield of interseeded alfalfa Prohexadione does not alleviate corn yield depression due to interseeding

Impacts of organic and inorganic fertilizations on alfalfa yield, soil nitrate and greenhouse gas emissions.

Field plot experiment was carried out during May 2012 to June 2014 to investigate the impacts of nitrogen fertilizations on the emissions of nitrous oxide (N2O) and methane (CH4) from alfalfa field as well as the dry matter yield and soil nitrate contents. Five treatments including CK, urea (100 kg N·hm-2, CF), urea (100 kg N·hm-2) + dairy cattle manure (60 kg N·hm-2) (DM1), urea (100 kg N·hm-2)+ digestate (60 kg N·hm-2) (DT) and reduced urea (40 kg N·hm-2)+ dairy cattle manure (60 kg N·hm-2) (DM2) were conducted. Results indicated that in comparison with CK, CF, DM1, DT and DM2 treatments significantly increased the dry matter yields of alfalfa by 44.2%, 38.9%, 56.3% and 30.6%, and increased the N2O emissions by 52.2%,89.1%, 133.7% and 59.4%, respectively, whereas the oxidation of atmospheric CH4 was reduced to different extents by these N management practices. The losses of N2O-N originated from urea and dairy cattle manure N accounted for 0.25%-0.28% of their inputs, whereas a greater va-lue of 0.64% was observed for digestate N. Applying urea or organic N to alfalfa field could significantly increase the dry matter yield without significant NO3--N leaching, however, it would lead to higher net CO2-equivalent emissions of producing 1 t dry matter of alfalfa.

Changing in organic carbon dynamics and biological activities in clay loam brown forest soil by application of municipal sewage sludge

A greenhouse pot experiment was conducted to assess the effects of two municipal sewage sludges (MSS) application on change in the dynamics of organic carbon, microbial population, enzymatic activities and alfalfa growth in relation to heavy metal content and nutrient release from sewage sludge in clay loam brown forest soil. The treatment of MSS increases soil organic matter and improves soil structure. Municipal sewage sludge of high heavy metal content (HHM) significantly decreased soil bioproductivity, reduced its biochemical properties, and lowered the microbial contents in comparison with MSS of low heavy metal (LHM) content. Total alfalfa dry matter yield and nitrogen content increases linearly with increasing MSS application rates. Soil treated with MSS rates of 40 and 60 % exhibit higher in crop dry matter, microbial contents and enzymatic activities than the control. Overall, our results demonstrate that soil treated with LHM content can improve soil quality and soil biological and biochemical properties.