We evaluated soybean (Glycine max (L.) Merr. cv. Ryuho) silage that was harvested at two growth stages by the direct cutting system used for corn-silage production. R6 (full-size green beans) and R7 (pods and 50% of leaves yellowed) growth stages of grain-type soybean were compared after being harvested with a corn harvester and ensiled with a round baler for chopped material. Dry matter (DM), crude protein (CP) and acid detergent fiber contents were higher for R7 silage than for R6 silage. The silage of both stages exhibited lactic-acid dominant fermentation, with no significant difference in ruminal effective DM degradability. R6 silage had higher volatile basic nitrogen in total nitrogen (P < 0.01) and a higher ruminal soluble CP fraction (P < 0.01) than R7 silage. In conclusion, although well-preserved silage was obtained from harvesting soybean at both R6 and R7 stages using the direct cutting system, R7 stage harvesting appeared to result in better conservation of protein quality.

Alfalfa (Medicago sativa L.) has been cultivated increasingly widely in the arable area of the middle-eastern regions of China as a short-term (1 or 2 years) component of a forage–grain rotation system, but little is known about the harvesting technique for this legume in the short-term rotation. This study investigated the effects of cutting height (0-, 5- and 10-cm stubble height above the soil surface) on shoot regrowth and forage yield of alfalfa in the second-year growing season at two sites in Shandong Province, China. Forage yield at the first harvest was higher under lower cutting height (0 > 5 > 10 cm) at both sites due to greater length and weight of individual shoots harvested. At the site where plants were fertilized and irrigated after the first harvest, lower cutting height increased the number of buds during the early regrowth period and the number of shoots per plant at the second harvest, though it decreased the length and weight of individual shoots harvested. At the site without fertilizer and irrigation, lower cutting height delayed the sprouting of buds after defoliation, and decreased the length of shoots harvested at the second cut. Forage yield at the second harvest was ranked 0 ≈ 5 > 10 cm under fertilizer and irrigation, and 0 ≈ 5 ≈ 10 cm under no fertilizer and irrigation. The path analysis showed that forage yield was affected primarily by the weight of individual shoots at the first cut and by shoot number per plant in the aftermath. Harvesting close to the ground is considered to be a management option to increase alfalfa yield in a short-term forage production system subjected to irrigation and fertilizer.

To identify the best ensiling process and moisture content for rice grain silage, we determined the effects of additive (i.e. no additive, glucose additive or lactic acid bacteria [LAB] inoculation), crushing process (non-crushing or crushing) and moisture control (none [13.6%], 20.0, 27.5, 35.0, 42.5 or 50.0% moisture content [in fresh matter, FM]) on rough rice and brown rice. Forage rice harvested at the fully ripe stage was ensiled in small-scale experiments, and the silage was stored for 60 days. Regardless of the use of additives or LAB inoculation, the pH values tended to decrease with increasing moisture content. LAB inoculation and crushing resulted in low pH values, low butyric acid contents, low ethanol contents and high lactic acid contents, and the lactic acid content increased to more than 2.0% in FM at moisture contents of 27.5% and higher. The parameters of fermentation quality (pH, lactic acid, butyric acid, volatile basic nitrogen and ethanol content) were affected by not only the main effect of additive, crushing process and moisture control but also two-way or three-way interaction effects. LAB inoculation and crushing improved the lactic acid fermentation under lower moisture conditions, that is, 27.5% moisture content. In both rough rice and brown rice, we suggest that the appropriate pretreatment is the combined use of LAB inoculation, crushing process and controlling 27.5% moisture content.

Potassium (K) management is important in grassland systems, especially in dairy farming. The interactions of K with other nutrients, such as magnesium (Mg), and enhanced K levels themselves can have impacts on metabolic health issues of dairy cattle, yields and product quality. A deeper understanding of K dynamics is necessary for sustainable management. We used four sandy soils of similar genesis but from fields contrasting in farm K management histories (>15 years) and combined these with different levels of mineral K fertilization in a 5-month glasshouse pot trial with Italian ryegrass (four cuts). The initial plant available soil K status (calcium–acetate–lactate extraction: K_CAL) was 18, 93, 168 and 295 mg K kg⁻¹ for low (organic), medium (organic), high (conventional) and very high (conventional) input farming systems, respectively. A mass balance approach was used to examine soil K history and treatment K fertilizer effects on soil and plant K. Potassium concentrations in shoots were high, except for the low K input soil under the 0 K fertilizer treatment, and were influenced by initial soil K and high K input. Soil K release values reflected K management history, whereby soils with higher historical K inputs released more K, and the organically managed low input soil had very limited K release and reserves. K_HCl was found to be a strong (R² = 0.87) and useful indicator of potential and available soil K deliveries from these sandy soils. This study has confirmed that both long-term K management history and current K fertilizer practice have strong effects on K and Mg dynamics in the soil–plant system.

Sorghum accumulates sugars (sucrose, glucose and fructose) in the stem after anthesis. Brix is commonly used to indicate total sugar content; however, the relationship between Brix and specific sugar components has not been sufficiently investigated in sorghum juice in Japan. In this study, we measured the sugar components of sorghum juices from 109 varieties using capillary electrophoresis, which can quantify each sugar component in crude juice without further purification. The results indicated that the Brix of sorghum juice was proportional to the total sugar and sucrose concentrations (r = 0.900 and r = 0.894, P < 0.01, respectively). Glucose concentration had a significant positive correlation with fructose concentration (r = 0.964, P < 0.01), but no correlation was detected between Brix and the two hexose sugars, glucose and fructose. Our results showed that sucrose comprised approximately 75% of the total sugar in varieties with Brix values greater than 15. These findings may be applied in sorghum breeding efforts to develop varieties that accumulate high levels of sugars in the juicy stems of sorghum plants.

A prototype software tool (Pasture Growth Simulation Using Smalltalk, PGSUS) was developed to estimate herbage mass at an individual paddock level so that farmers can measure herbage mass less frequently. PGSUS was tested on 10 commercial and two research dairy farms in New Zealand. Herbage mass estimations from PGSUS were accurate, with an average residual standard deviation of 252 kg dry matter ha⁻¹ across all farms. When interviewed, all farmers gave high ratings to PGSUS, except for the amount of data collection required, and user friendliness, which were given a medium ranking. The extra time dedicated to PGSUS by farmers was 43 min per week on average, which was judged acceptable by farmers. However, in practice, the participating farmers were unable to enter all the information required for the system to work as intended. It is concluded that while it is technically possible to use a pasture model to estimate herbage mass at paddock level with sufficient accuracy to aid decision making, the recording of grazing events proved to be a major obstacle. If the issue of data entry can be overcome, it is envisaged that a full commercial version of PGSUS should appeal to objective-data-oriented farmers, most probably as an add-on to existing commercial farm software.

Three of the main management factors affecting herbage chemical composition pre-ensiling are plant species, rate of nitrogen (N) fertilizer application and stage of maturity at harvest. This study investigated the effects of N fertilizer input and harvest date in the spring growth on the fermentation characteristics, dry matter recovery and aerobic stability of silages prepared from five common grass species. Perennial ryegrass (Lolium perenne cv. Gandalf), Italian ryegrass (Lolium multiflorum cv. Prospect), tall fescue (Festuca arundinacea cv. Fuego), cocksfoot (orchardgrass, Dactylis glomerata cv. Pizza) and timothy (Phleum pratense cv. Erecta) were grown under two inorganic N fertilizer inputs (0 and 125 kg N ha⁻¹), harvested at five dates in the spring growth (fortnightly from 12 May to 7 July; Harvests 1 to 5, respectively) and subsequently ensiled in laboratory pipe silos for a period of 100 days. The ryegrass and tall fescue silages exhibited a lactic acid dominant fermentation and showed little evidence of secondary clostridial activity. In contrast, the challenge to preservation proved greater for the timothy (Harvests 1 and 2) and cocksfoot (Harvests 1 and 5) herbages, with the high pH (>4.2) and high butyric acid (>10 g kg⁻¹ dry matter) and ammonia-N (>100 g kg⁻¹ N) concentrations being indicative of secondary clostridial activity during storage. Despite the effects on herbage chemical composition prior to ensiling being indicative of a greater challenge to preservation, there was little effect of fertilizer N on the extent or direction of fermentation. Although the Italian ryegrass herbage avoided significant clostridial activity, this herbage incurred the greatest dry matter losses during ensiling. This was particularly evident at early harvest dates suggesting yeast fermentation of sugars, which were surplus to the requirement for a lactic acid dominant fermentation.

Assessment of grazing-induced degradation of arid and semiarid rangelands with stochastic rainfall regimes is challenging. To assess grazing impacts on vegetation under highly variable environments, we focused on resource variations in relation to the scale of local rangeland use. Specifically, we tested the hypothesis that grazing impacts on resources were greater in areas heavily used during drought (i.e. key resource areas) than elsewhere. Near Mandalgobi, Mongolia, we established study sites in four typical vegetation communities (Caragana, Allium, Achnatherum and Reaumuria) according to landscape type. First, we interviewed key informants about the four community types to examine how local pastoralists used these communities during normal and drought summers. Second, we compared dung pellets numbers among communities to quantify the different grazing impacts on each community. Finally, to determine grazing impacts on vegetation in each community, we performed vegetation surveys in grazing and non-grazing plots at each site. According to respondents, during normal summers all types of community were used, but during drought, the main community used was Achnatherum community. The number of dung pellets was highest in the Achnatherum community. Species composition was significantly more affected by grazing in the Achnatherum and Reaumuria community than in the other communities. These results suggested that the Achnathrum community would have a role of key resource in study sites and grazing impacts affected key resource areas. If rangeland management is focused only on maintaining resource accessibility, then grazing-induced degradation of key resource areas could occur even on highly variable rangelands.

Proper harvest timing of sudangrass [Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet & Harlan] for hay or silage is a compromise between optimized nutrient quality and yield. Brown-midrib (BMR) sudangrass varieties have reduced lignification and cell wall concentration resulting in increased digestibility. Non-BMR and BMR sudangrasses were no-till seeded and harvested at either the boot or dough grain stages of maturity. When harvested at the boot stage of maturity, there was no difference (P = 0.93) in dry matter (DM) yield between the BMR and non-BMR varieties; while harvesting at the dough grain stage of maturity the BMR variety produced more DM than the non-BMR variety (P < 0.01). Dry matter and detergent fiber content increased (P < 0.01) and crude protein and calculated total digestible nutrients (TDN) content decreased (P < 0.01) with increasing maturity in both varieties. Regardless of maturity, neutral detergent fiber and acid detergent fiber were less (P < 0.01), and TDN content was greater (P < 0.01) for the BMR sudangrass compared with the non-BMR variety. Presence of the BMR gene had no effect (P = 0.99) on in situ effective degradability when sudangrass was harvested in the boot stage, but effective degradability was greater (P < 0.01) in BMR sudangrass when harvested in the dough stage of maturity. Inclusion of BMR genetics did not affect performance or digestion kinetics when silage harvested in the boot stage of maturity was fed to growing steers. Brown midrib genetics provide significant advantages when forages are harvested at advanced stages of maturity, but advantages are not as pronounced when forage is less mature.

We describe changes in plant diversity and productivity after the abandonment of public pastures in Japan. We surveyed the plant community and collected plant and soil samples from 22 pastures, including five pastures that had been abandoned up to 13 years earlier. Chemical analysis revealed forage nutritive values and soil nutrient levels. Overall, plant diversity did not change over time, but productivity and forage nutritive values both decreased significantly after pasture abandonment. These changes can be explained by (i) lower soil nitrate–nitrogen contents due to leaching and (ii) the replacement of sown grasses by native species. Our results suggest that it will become more difficult to restore pasture for grazing as the duration of abandonment increases and that reintroduction of livestock grazing in the abandoned pastures without re-sowing exotic grasses could contribute to biodiversity conservation and maintaining productivity and nutritive values.