Effects of Fertilizer Rate and Row Spacing on Forage Soybean (Glycine max [L.] Merrill) Biomass Yield and Quality in the Highlands of Ethiopia

Kenaf (Hibiscus cannabinus L.) forage potential can be enhanced through its regrowth capacity and higher production in narrow rows. A field experiment was conducted in Matamoros, Coahuila, Mexico, during 2 growing seasons (2004 and 2005) to study the effects of plant height and row spacing on kenaf forage potential with multiple harvests. This study evaluated the effects of (1) 2 plant heights at cutting (1.0-1.2 m and 1.8-2.0 m) and (2) 4 inter row spacings (0.19, 0.38, 0.57 and 0.76 m) using a 2 x 4 factorial arrangement of treatments in a completely randomized block design with 4 replications. Dry matter (DM) and crude protein (CP) yields, DM partitioning, neutral detergent fiber (NDF) and CP concentrations were determined. Heights at cutting × row spacing interactions were not significant for the monitored variables (p>0.05). Kenaf response to treatments was only relevant for main effects (p≤0.05). Row spacing and plant height affected DM and CP yields (p≤0.05), whereas only plant height affected chemical composition and DM partitioning (p≤0.05). Dry matter (17.0%-26.0%), and CP (12.4%-15.6%) yields were higher (p≤0.05) when plant heights had reached 1.8 to 2.0 m. Row spacing reduction from 0.76 m to 0.38 and 0.19 m increased DM yield (20.4-33.4%) and CP yield (24.2-38.5%) (p≤0.05). Kenaf forage potential increases when planted in narrow rows and harvested 2 or 3 times during the growing season.

Corn is an important cereal crop in Ethiopia due to its use as a source of food security. However, its productivity is limited by insufficient application of the NPS fertilizer and different row spacing. A field trial was carried out to assess the effects of the application of different NPS fertilizer quantities and inter row spacing on the growth, yield components and yield of maize and the cost-benefit analysis of the NPS compound fertilizer application on the yield of maize in the main growing season 2019/2020.The study was arranged in a factorial combination of five levels of NPS fertilizers (0, 50, 100, 150 and 200 kg NPS ha-1) and four inter row spacing (55 cm, 65 cm, 75 cm and 85 cm). in a randomized complete block design with three replications. The consequence showed the main result of the NPS fertilizer had a highly significant (p <0.01) effect on days up to 50% anthesis, days up to 50% silk formation, 90% physiological maturity, leaf area, leaf area index, number of plants at harvest, the number of grains per ear was determined from the main effects of NPS fertilizer of 200 kg NPS ha-1. The interaction effects of NPS and row spacing have highly significant (p <0.01) effects on the number of ears per plant, number of ears per hectare, ear length, agronomic effectiveness and grain yield were obtained when using 150 kg. measured NPS ha-1 at 75 cm row spacing. The highest economic (91,608 Birr ha-1) and a higher MRR (1745%) resulted from the 150 kg NPS ha-1 and 75 cm row spacing. Thus, it should be noted that the application of 150 kg NPS ha-1 with a row spacing of 75 cm was both agronomic and cost-effective for the grain yield of the Melkassa-II in the study area.

Abstract‘Piper’ sudangrass, a sudangrass hybrid ‘Trudan II,’ and six sorghum ✕ sudangrass hybrids were variously managed in 1965 and 1966 to provide yield and compositional data. At heights of 46 cm (management A), five harvests resulted; at 92 cm (B), three harvests; at 137 cm (C), two harvests; and hard dough (D), one harvest. Percentages of crude protein and in vitro digestible dry matter (IVDDM) were highest for frequently harvested forage. Yields of dry matter, crude protein, and IVDDM were 27, 10, and 22% greater, respectively, for A (5 harvests) over B (3 harvests). Comparing B to C (3 to 2 harvests) total crude protein yields decreased 4% but dry matter and IVDDM yields increased 23 and 18%, respectively. From C to B (2 to 1 harvest) yields of dry matter, crude protein, and IVDDM were 86% more, 17% less, and 52% more, respectively. Piper was generally inferior to either Trudan II or one or more of the sorghum ✕ sudangrass hybrids. Trudan II was significantly higher yielding in dry matter, crude protein, and IVDDM over all managements as compared to Piper.Over all managements, Trudan II was significantly higher in crude protein yield than the mean of six sorghum ✕ sudangrass hybrids whereas differences in yields of dry matter and IVDDM were not significant. Sorghum ✕ sudangrass hybrids were definitely superior under D (1 harvest) management. While the sorghum ✕ sudangrass hybrids and Trudan II were both superior to Piper under multiple harvest (A,B,C managements), the sudangrass hybrid (Trudan II) should be given strong consideration because of its known advantage in lower prussic acid potential.

Livestock production contributes to the livelihoods of the Ethiopian people; however, the productivity of the livestock subsector in the highlands is low due to malnutrition. Therefore, this study assessed the botanical composition, dry matter (DM) yield, chemical composition and in vitro dry matter digestibility (IVDMD) of the grassland. The study was conducted in a 3 × 4 factorial experiment arranged in a randomised complete block design with three replications. The treatments were three harvesting times (60, 90 and 120 d after regrowth) and four nitrogen (N) fertiliser levels (0, 50, 100 and 150 kg ha−1). Harvesting at 90 d and application of 100 and 150 kg ha−1 N fertiliser had a higher (P < 0.05) total DM yield of the grassland. Crude protein, neutral detergent fibre, acid detergent fibre, cellulose, hemicellulose, phosphorus and IVDMD were significantly (P < 0.05) affected by the stage of harvesting. However, N fertiliser had no significant effect on chemical composition and IVDMD of the grassland. The results confirmed that the grassland can be categorised as medium- to high-quality herbage if harvested at 90 d after regrowth. Further studies on animal performance and feed intake to develop grassland-based diets are suggested for smallholder livestock producers in the highlands of Ethiopia.

Application of herbicides caused significant reduction in weed density and weed dry matter. The maximum reduction in weed density and weed dry matter was recorded in the plots treated with metribuzin followed by isoproturon and sulfosulfuron at 45 DAS and at harvest. Herbicidal treatments significantly increased number of tillers 45 DAS and plant height at 90 DAS and at harvest. The dry matter accumulation by crop at all the growth stages was significantly higher under isoproturon which was closely followed by sulfosulfuron.The maximum value of effective tillers, ear length, number of grains ear -1 and test weight were observed with isoproturon followed by sulfosulfuron. Consequently, isoproturon produced significantly higher grain (5.72 t ha -1 ) and biological yield (12.64 t ha -1 ) and also net return (83753 Rs. ha -1 ) compared to other treatments. The effect of row spacing was significant on density and dry matter of weeds at 45 DAS and at harvest. The minimum density of weeds was observed under row spacing of 17.5 cm which was closely followed by 20.0 cm and both these had significantly lower than 22.5 cm in this respect. Row spacings did not have significant impact on plant height. The maximum number of effective tillers was recorded under 20.0 cm whereas dry matter accumulation was under 22.5 cm row spacing. Sowing at 17.5 cm row spacing produced significantly higher grain (4.94 t ha -1 ) and biological yield (11.94 t ha -1 ) also net return (71314 Rs. ha -1 ) compared to other row spacing.

Legume forage, like vetches, is an important feed source for animals as a supplement to low-quality feeds. This study was conducted to evaluate the forage yield and nutritional values of vetches intercropped at various spacings of desho grass. The study was designed in a factorial arrangement with a randomized complete block design with three inter-row spaces (0.50 m, 0.75 m, and 1 m) and intercropping two vetches (&amp;lt;i&amp;gt;Vicia sativa&amp;lt;/i&amp;gt; ICARDA 61509 and &amp;lt;i&amp;gt;Vicia dasycarpa&amp;lt;/i&amp;gt; lana) and desho grass with three replications. Agronomic parameters, forage and seed yield, chemical analysis, and in vitro digestibility of vetch forage samples were determined. Results showed that significant differences (p&amp;lt;0.05) were observed for all measured agronomic parameters of vetches, except leaf length, due to spacing and interaction effects. Dry matter yield of vetch (DMY) was only affected by row spacing, while crude protein yield (CPY) was affected by row spacing and their interactions. Higher DMY (3.87 - 4.04 t/ha) and CPY (0.74 - 0.79 t/ha) were obtained from solely grown vetches as compared to intercropped vetches (2.26 - 2.42 t/ha and 0.417 - 0.423 t/ha), respectively. Forage yield significantly decreased as row spacing increased. Seed yield decreased as the row space increased, and the yield obtained from &amp;lt;i&amp;gt;Vicia sativa&amp;lt;/i&amp;gt; ICARDA 61509 was higher (0.6 and 1.23 t/ha) than &amp;lt;i&amp;gt;Vicia dasycarpa&amp;lt;/i&amp;gt; lana (0.41 and 0.82 t/ha) when either intercropped with desho grass or sown alone, respectively. The interaction of intercropping with spacing unaffected vetch&amp;apos;s chemical composition. However, crude protein (CP) and acid detergent lignin of vetches were influenced by intercropping, whereas CP, neutral detergent fiber, and acid detergent fiber were affected by spacing (p&amp;lt;0.05). Intercropped &amp;lt;i&amp;gt;Vicia dasycarpa&amp;lt;/i&amp;gt; gave higher in vitro dry matter digestibility (IVDMD), &amp;lt;i&amp;gt;in vitro&amp;lt;/i&amp;gt; organic matter digestibility, and metabolizable energy than &amp;lt;i&amp;gt;Vicia sativa&amp;lt;/i&amp;gt;, and IVDMD increased as row spacing increased from 0.5 to 1 m.

Napier grass (Pennisetum purpureum (L.) Schumach.) was studied using a 5 x 3 factorial experiment arranged in a randomised complete block design with three replications. The treatments were five fertiliser applications (0kg ha-1 N, 46kg ha-1 N and 92kg ha-1 N, 1t ha-1 and 2t ha-1 cattle manure) and three plant heights at cutting (0.5m, 1m and 1.5m). The mean dry matter (DM) yield was 8.21t ha-1 per cut but increased when the plant height at cutting increased and when the level of N fertilisation increased (P<0.05). Neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), cellulose, calcium, in vitro dry matter digestibility (IVDMD) and metabolisable energy were significantly (P<0.05) affected by plant height at cutting while total ash, crude protein (CP), ADF-ash, hemicelluose and phosphorus were affected by both plant height at cutting and fertiliser level. As plant height at cutting increased from 0.5m to 1.5m, IVDMD declined from 71.74% to 61.03% (P<0.05). Correlations between IVDMD versus CP, NDF, ADF, ADL, cellulose and hemicellulose were high with r = 0.92, -0.94, -0.96, -0.98, -0.83 and 0.74, respectively. CP yield per hectare per day of growth was highest for the 0.5m height at cutting, whereas the digestible DM yield was highest at both the 0.5m and 1.0m cutting height. The results of the present study suggest that Napier grass could be categorised under medium to high quality forage if cut at 0.5m or 1.0m height.

The study was conducted during the main cropping season of 2019/2020 at Assosa in Benishangul-Gumuz regional state. The aim of the study was to evaluate herbage dry matter yield, nutritional quality and biological compatibility of desho grass mixed with Stylo and Desmodium. The treatments included two legume species (Stylosanthes guyanensis and Desmodium unicinatum) and desho grass with four levels of seed proportions (100%, 75%, 50% and 25%) of the recommended seeding rates of the two legume forages. Randomized complete block design with four replications was used. The results revealed that number of tillers per plant (NTPP), plant height (PH) and leaf to stem ratio (LSR), plot cover and vigor score percentage, dry matter yield (DMY) tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;, and the quality parameters such as, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent Lignin (ADL), In-vitro Dry matter Digestibility (IVDMD) and crude protein yield (CPY) tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; were significantly (P&amp;lt;0.05) differed among the different seed proportions of desho grass with legume mixtures. The highest total dry matter yield (11.05 t ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) was obtained from the sole desho grass planted with Nitrogen fertilizer followed by sole desho grass planted without fertilizer (10.17 t ha&amp;lt;sup&amp;gt;-1 &amp;lt;/sup&amp;gt;) from the mixed cropping groups mixed crop containing 75% desho grass and 25% Stylo gives a higher total dry mater yield (7.44 tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;). On the other hand desmodium sown in pure stands had lower DMY compared to legume-grass mixtures (3.37tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;). In terms of quality, increasing the seed proportions of both legume species in the mixture resulted in higher CP%, CPY (tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) and IVDMD% and lower NDF%, ADF% and ADL% contents. Relative yield total of desho grass-legume mixtures at Desho&amp;lt;sub&amp;gt;75 &amp;lt;/sub&amp;gt;Stylo&amp;lt;sub&amp;gt;25 &amp;lt;/sub&amp;gt;(1.43), Desho&amp;lt;sub&amp;gt;50 &amp;lt;/sub&amp;gt;Desmodium &amp;lt;sub&amp;gt;50 &amp;lt;/sub&amp;gt;(1.39) and Desho&amp;lt;sub&amp;gt;25 &amp;lt;/sub&amp;gt;Stylo&amp;lt;sub&amp;gt;75 &amp;lt;/sub&amp;gt;(1.33) were better compared to the other mixtures and pure stands. Generally, mixing of desho grass with legume species at different seed proportions of 75% desho grass: 25% stylo and 50% desho grass: 50% Stylo produced better dry matter yield, nutritional quality and compatibility in the study area when compared to the mixed cropped plants. However, the experiment should be conducted for more years at different locations to recommend the best desho grass legume mixtures for Assosa area of Benishangul-Gumuz Regional State. It is also suggested to do on animal performance trial of this result based on animal feeding practice and economic feasibility in order to come up with sound recommendations.

Application of organic and inorganic fertilizers is essential for sustainable production of crops including potato. This study was therefore initiated to identify the optimum rate of farmyard manure (FYM) and blended compound NPS fertilizer for profitable production of potato in Koga Irrigation Scheme, Northwestern highlands of Ethiopia. Four rates of FYM (0, 4.5, 9, and 13.5 t ha−1) and NPS fertilizer (0, 81.7, 163.4, and 245.1 kg ha−1) were laid down in Randomized Complete Block Design with three replications. The results revealed that FYM and blended NPS fertilizer as well as their combination influenced most of the tested growth and yield parameters of potato including plant height, main stem number, and tuber weight. Application of 245.1 kg ha−1 NPS combined with 13.5 t ha−1 FYM recorded the highest marketable and total tuber yields of 43.52 and 47.04 t ha−1, respectively. Although, the highest marginal rate of return was obtained from plants supplied with the combination of 4.5 t ha−1 FYM and 163.4 kg ha−1 NPS fertilizer, combined application of 245.1 kg ha−1 NPS and 13.5 t ha−1 FYM is recommended for economical production of potato in the study area as it recorded the highest net benefit with acceptable marginal rate of return.

Considerable interest exists in New York for narrow row corn (Zea mays L.) silage production because farmers, who converted from 30- to 15-in. row spacing, report yield increases of 3 to 4 tons/acre. We evaluated eight hybrids at densities of 18 000, 24 000, 30 000, 36 000, and 42 000 plants/acre in 1994, 1995, and 1996 to compare yield, quality, and economics of corn silage production at 15- and 30-in. row spacings. When averaged across years, hybrids, and densities, corn silage yielded 24.9 tons/acre at 15 in. and 23.9 at 30 in. row spacing. Row spacing × hybrid and row spacing × plant density interactions did not exist. When averaged across years, hybrids, and row spacings, maximum economic yields occurred at about 39 500 plants/acre. In vitro true digestibility (IVTD), however, had a 0.1% decrease and neutral detergent fiber (NDF) had a 0.13% increase per 1000 plant/acre increase. Consequently, estimated maximum economic milk yield occurred at about 35 000 plants/acre. Partial budget analyses indicated that farmers who produce 200 acres of corn silage might expect a slight loss in annual net farm income (-$696) with the conversion from 30- to 15-in. row spacing. Farmers, who produce 400 and 800 acres of silage, might expect modest ($3116) and significant gains ($11 624) in annual net farm income, respectively. We have initiated field-scale trials on a dairy farm to further assess the potential for narrow row corn silage production in New York.

Increasing seeding rate and widening row spacing to allow for between row cultivation may reduce weed competition in organic canola (Brassica napus L.) production. Research was conducted to evaluate the effects of row spacing and seeding rate on canola population, weed competition, and yield in organic canola production. Canola variety Hornet was planted at five seeding rates (3.4, 6.7, 10.1, 13.4, and 16.8 kg ha−1) at three row spacings (17, 34, 68 cm) in Goldsboro, Kinston, and Salisbury, NC, in 2011 and 2012. Between row cultivation was performed in the 68‐cm row spacing as weather permitted. Canola population increased with increasing seeding rate across all row spacings, and canola populations were highest with the 17‐cm row spacing, followed by the 34‐ then 68‐cm row spacings. Yield was similar across row spacings at the lower seeding rates in five of the six environments. At these environments, yield tended to increase in the 17‐cm row spacing as seeding rate increased but declined in the 68‐cm row spacing with increasing seeding rate. In one environment with a unique weed community, weed suppression and yield were higher with the 68‐cm row spacing. It was concluded that the yield plasticity of canola will provide producers flexibility in selecting row spacing, and seeding rate selections should be based on desired row spacing.Core Ideas Increasing canola seeding rate and widening row spacing to allow for between row cultivation may serve as mechanisms to reduce weed competition in canola production, but have rarely been evaluated in organic production. This study was conducted to evaluate seeding rate and row spacing effects on weed competition and yield in organic canola production. Despite different canola populations across canola row spacings, yield tended to be similar at low seeding rates across the row spacings indicating canola has the ability to compensate for low population. Depending on the weed species at your environment, widening row spacing to allow for between row cultivation may prove critical for reducing weed competition and increasing canola yield. Yield tended to increase with increases in seeding rate at the 17‐cm row spacing, however yield declines were observed with higher seeding rates in the 68‐cm row spacing, which is likely attributed to intraspecific competition. Organic canola producers have flexibility when selecting row spacing and seeding rates due to the great plasticity of canola.

To determine the suitable planting density and row spacing of short-season cotton suitable for machine picking in the Yellow River Basin of China, we conducted a two-year field experiment in Dezhou during 2018-2019. The experiment followed a split-plot design, with planting density (82500 plants·hm-2 and 112500 plants·hm-2) as the main plots and row spacing (equal row spacing of 76 cm, wide-narrow row spacing of 66 cm+10 cm, equal row spacing of 60 cm) as the subplots. We examined the effects of planting density and row spacing on growth and development, canopy structure, seed cotton yield and fiber quality of short-season cotton. The results showed that plant height and LAI under high density treatment were significantly greater than those under low density treatment. The transmittance of the bottom layer was significantly lower than under low density treatment. Plant height under 76 cm equal row spacing was significantly higher than that under 60 cm equal row spacing, while that under wide-narrow row spacing (66 cm +10 cm) was significantly smaller than that under 60 cm equal row spacing in peak bolling stage. The effects of row spacing on LAI varied between the two years, densities, and growth stages. On the whole, the LAI under the wide-narrow row spacing (66 cm+10 cm) was higher, with the curve declining gently after the peak, and it was higher than that in the two cases of equal row spacing in the harvest time. The change in transmittance of the bottom layer presented the opposite trend. Density, row spacing, and their interaction had significant effects on seed cotton yield and its components. In both years, seed cotton yield was the highest (3832 kg·hm-2 in 2018, 3235 kg·hm-2 in 2019) under wide-narrow row spacing (66 cm+10 cm), and it was more stable at high densities. Fiber quality was less affected by density and row spacing. To sum up, the optimal density and row spacing of short-season cotton were as follows: density with 112500 plants·hm-2 and wide-narrow row spacing (66 cm+10 cm).

본 연구는 국내 개발 이탈리안 라이그라스 (IRG)의 봄철 1회 및 2회 이용 시 수확적기를 구명하고자 국립축산과학원(수원)에서 조생종 'Kowinearly' 품종을 공시, 2009년 9월 30일에 파종하여 2010년 6월까지 수행하였다. 처리내용은 1차 수확시기로 출수시(T1), 출수기(T2), 출수후기~개화초기(T3), 개화기~개화후기(T4), 등숙기(T5) 및 등숙후기(T6) 등 6처리였으며, 2차 수량조사는 6월 11일 동일하게 실시하였다. 'Kowinearly'의 출수시는 5월 4~5일, 출수기는 5월 14일, 도복은 개화 이후 많이 관찰되었다. 건물률은 T1 14.8%에서 T6 35.0%로 생육진행에 따라 높아졌으며, 조단백질, RFV, 건물 소화율 등 사료가치는 생육 지연에 따라 낮아졌다. 건물수량과 가소화 건물수량은 T4에서 ha당 각각 8,984 kg과 5,728 kg으로, 조단백질 수량은 T3에서 795 kg으로 유의적으로 높았으며 (p<0.05), 재생초의 건물수량, 조단백질 수량, 가소화 건물수량은 T1과 T2에서 차이 없이 각각 5,425 kg, 596 kg, 3,204 kg(T1)과 4,811 kg, 589 kg, 3,143 kg (T2)으로 유의적으로 높았다 (p<0.05). 총 건물수량, 조단백질 수량, 가소화 건물수량은 T2 와 T3에서 차이 없이 각각 11,089 kg, 1,254 kg, 7,669 kg(T2)과 10,354 kg, 1,225 kg, 6,915 kg (T3)으로 유의적으로 높았다 (p<0.05). 일당 건물생산량과 일당 가소화건물생산량은 1차 생육은 T2, T3, T4에서, 재생초는 T2, T1에서 높았으며, 전 기간 일당생산량에서는 출수기인 T2에서 가장 높았고 다음이 T3, T4, T1 순이었다. 이상의 결과를 종합하여 볼 때, IRG 'Kowinearly'를 봄철에 1회 수확하여 이용할 경우 단위면적당 생산량과 사료가치를 고려한 수확적기는 출수후기~개화기이며, 봄철 2회 수확하여 이용할 경우 재생과 단위면적당 총 생산량을 고려한 1차 수확적기는 출수기가 유리하다고 판단된다. This study was carried out to determine the optimum harvest stage of Italian ryegrass (Lolium multiflorum Lam., IRG) for maximum forage production during the spring season in Suwon, 2010. The variety of IRG was the early maturity type, 'Kowinearly', and six harvest stages (treatments) were first heading (T1), heading (T2), late heading to early bloom (T3), bloom to late bloom (T4), ripeness (T5), and late ripeness stage (T6). The dates of the first heading and heading of 'Kowinearly' were seen on 4 to 5 May, and 14 May, respectively. Plant length and dry matter (DM) percentage at first harvest were from 69 cm and 14.8% at T1 stage to 103 cm and 35.0% at T6 stage, respectively. The content of crude protein (CP) and in vitro DM digestibility (IVDMD) of T1, T2, T3, T4, T5 and T6 at first harvest were 15.6%, 10.6%, 10.1%, 8.1%, 7.3% and 5.4%, and 81.8%, 72.1%, 64.8%, 63.8%, 61.4% and 59.0%, respectively. The content of neural detergent fiber (NDF) and acid detergent fiber (ADF) were increased continuously with delayed harvest. A significantly higher yield of DM, CP and in vitro digestible DM (IVDDM) were observed for T3, and T4 (p<0.05). DM yield of 3,526 kg, 6,278 kg, 7,842 kg, 8,984 kg, 8,346 kg and 8,008 kg/ha, CP yield of 549 kg, 665 kg, 795 kg, 725 kg, 608 kg and 430 kg/ha, and IVDDM of 2,883 kg. 4,526 kg, 5,083 kg, 5,728 kg, 5,124 kg and 4,722 kg/ha at first harvest were recorded in T1, T2, T3, T4, T5 and T6, respectively. Regrowth yield of DM, CP and IVDDM were shown to be higher at T1 and T2 (p<0.05). However, no significant differences were observed between the two stages. Daily DM and DDM production of regrowth IRG were higher at T2, followed by T1. The total yield (at first and at regrowth) of DM, CP and IVDDM were significant higher for T2, followed by T3, T4 and T1 in order. At T2 stage, the yield was 11,089 kg, 1,254 kg, and 7,669 kg/ha in DM, CP, and IVDDM. In conclusion, the late heading to bloom stage was determined to be the optimum harvest stage for a single harvest, while the heading stage was a suitable stage of first harvest of 'Kowinearly' where two harvests were sought in a single year.

Scientific and reasonable planting densities are crucial for Poa species forage production. However, the optimal row spacing and seeding rate for Poa species cultivation, and the effects of row spacing and seeding rate on Poa species forage yield in the Qilian Mountains remain unclear. In the current study, P. sinoglauca Ohwi., P. crymophila Keng, P. pratensis L. var. anceps Gaud, and P. pagophila Bor were selected as study materials, and a split field experiment designed with row spacing as the main factor and seeding rates as the sub-factor was conducted to study the effects of different row spacings and seeding rates on the agronomic traits and forage yield benefits of Poa species. The main plots were designed with different row spacings of 15 cm (R1), 30 cm (R2), and 45 cm (R3), and the subplots were designed with different seeding rates of 7.0 kg·hm-2 (S1), 12.0 kg·hm-2 (S2), and 17.0 kg·hm-2 (S3). A subsection structural equation model was used to analyze the influence process and path coefficients of row spacing, seeding rate, and the interaction between row spacing and seeding rate on the yield of Poa species, and the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) was used to comprehensively assess the agronomic traits and forage yield of the experimental varieties. Our results showed that row spacing significantly affected the plant height, tiller number, fertile tiller number, and forage yield of the four Poa species, while seeding rate and interaction between row spacing and seeding rate had significant effects on the forage yield of the four Poa species. The highest forage yields of P. sinoglauca (6709.1 kg·hm-²) and P. crymophila (7471.3 kg·hm-²) were recorded for a row spacing of 30 cm and seeding rate of 17 kg·hm-², and the highest forage yields of P. pratensis L. var. anceps (9469.0 kg·hm-²) and P. pagophila (8152.7 kg·hm-²) were recorded for a row spacing of 30 cm and seeding rate of 12 kg·hm-². Structural equation modeling indicated that row spacing, seeding rate, and the interaction between row spacing and seeding rate primarily affected the forage yield of Poa species by affecting plant height. Our research provided optimal sowing and row spacing for Poa species depending on the species to optimize forage production in the southern Qilian Mountains and similar areas.

Verificaram-se, durante o período seco, as composições químico-bromatológicas da forragem colhida em pastagem diferida de Brachiaria decumbens por dois métodos, forragem total (FT) e extrusa (EXT); as composições químico-bromatológicas; e as frações de proteína e carboidratos dos componentes folha verde (FV), caule verde (CV), folha seca (FS) e caule seco (CS). A FT apresentou proteína bruta (PB) inferior a 2,5%; a fibra em detergente neutro (FDN), superior a 78%; a lignina, superior a 8,7% na MS; e a digestibilidade in vitro da matéria seca (DIVMS), de 43,5%. A EXT apresentou maior DIVMS e maiores teores de PB, proteína insolúvel em detergente neutro e ácido, cinzas e fósforo e menores teores de fibras, carboidratos totais (CHT) e magnésio, quando comparado com FT. Verificaram-se maiores DIVMS e teores de PB, carboidratos não fibrosos (CNF), fósforo e potássio no componente FV e maiores teores de CHT e FDN nos componentes CV, FS e CS. Observaram-se altos valores da fração A da PB nos componentes FV e CV, baixos valores em FS e CS e altos valores da fração C da PB em CV, FS e CS. As concentrações das frações potencialmente digestíveis da PB, com exceção da fração B1, e de CNF, correlacionaram-se com o teor protéico nos componentes FV, CV, FS e CS. Em relação aos CHT, verificaram-se baixos valores de CNF e altos da fração C nos componentes CV, FS e CS.