Evaluation of corn-soybean inter-cropping systems in southwestern Japan

To assess the effects of inter-cropping corn and soybean under southwestern Japan’s climatic conditions, 5 different treatments were compared, namely: CW (mono-cropped corn - weeded); CTW (corn + soybean cv. Tachinagaha - weeded); CT (corn + soybean cv. Tachinagaha - unweeded); CSW (corn + soybean cv. Suzukaren - weeded); and CS (corn + soybean cv. Suzukaren - unweeded). Parameters measured were height, yield, nutrient composition of corn and soybean and the numbers of Japanese beetles (Popillia japonica). Plant height of mono-cropped corn was significantly (P<0.05) greater than that of corn in most of the inter-cropped treatments. The number of Japanese beetles had increased dramatically, especially on unweeded inter-cropped treatments, at 55 DAS (days after sowing). Fresh and dry matter yields (FMY and DMY) of corn did not differ among treatments (P>0.05), while CTW treatment produced higher FMY and DMY for soybean (P<0.05) than in CSW and CS. Weeding tended to reduce the number of Japanese beetles on soybean plants, but it did not affect yield of soybean in this study. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations in corn cobs, whole corn plants and whole soybean plants did not differ among treatments (P>0.05), while crude protein (CP) concentration in whole corn plants in CTW exceeded (P<0.05) those for mono-cropped corn and CSW treatments. These results indicated that soybean can be successfully inter-cropped with corn in southwestern Japan. Soybean plants may be infested with Japanese beetles. It is advisable to control weeds in the stands to reduce the level of beetle infestation and to minimize competition for the planted crops.

Quality properties of sunn hemp (Crotalaria juncea L.) and maize (Zea mays L.) silages

Maize is an ideal forage crop for ensilage because of its high levels of fermentable carbohydrates, although it is low in protein. Sunn hemp is a legume with a high crude protein content with potential to be used in combination with maize to provide a silage with a higher protein content. Different percentages of sunn hemp-maize mixtures of 80-20, 60-40, 40-60 and 20-80 respectively were compared to silages of sole maize and sunn hemp. In the laboratory study, DLG classifications (color, smell, structure, total score and quality class), silage loss (%), silage pH, dry matter content, flieg score, crude protein content, crude ash content, NDF, ADF, metabolic energy (MJ kg-1 DM), dry matter intake, percent digestible dry matter and relative feed value were determined at the end of 60 days ensilage. The crude protein contents of silages increased as the sunn hemp ratio in the mixtures increased. In addition, pure sunn hemp silage and mixtures, especially 80% sunn hemp mixed with 20% maize, were found suitable for silage and it was concluded that sunn hemp and sunn hemp-maize silage mixtures could be used in animal husbandry.

50 years publishing on tropical forages - from Tropical Grasslands and Pasturas Tropicales to Tropical Grasslands-Forrajes Tropicales

Preamble of the Volume 9, Issue 3

The effects of increasing concentrations of Trichanthera gigantea leaves in pellets on the nutritive value and short-term intake of diets of grass plus pellets offered to lambs reared under tropical conditions in the Caribbean

There is currently limited information on the benefits of increasing the concentration of Trichanthera gigantea leaves in pelleted diets offered to lambs reared under tropical conditions in the Caribbean. Twelve crossbred Barbados Blackbelly rams aged 5 months were used to determine the effects of increasing the concentrations of T. gigantea in pelleted diets, on the nutritive value and intake of grass forage plus pellets offered to lambs. Animals were randomly assigned to a basic diet (4 kg) of chopped Cenchrus purpureus plus 1 of 6 pelleted diets (500 g) comprised of either 100% intact commercial pellets or a pelleted mixture of ground commercial pellets and ground (dry fallen) T. gigantea leaf in the following ratios (T. gigantea leaves:ground commercial pellets): 20:80 (T20); 40:60 (T40); 60:40 (T60); 80:20 (T80); and 100:0 (T100). Total intakes of forage and pellets (TPI) were measured at the end of each day during a period of 7 days, and the average daily nutrient intakes of the different treatment diets were calculated. Overall, there was no significant difference in the intakes of pellets containing 0 to 80% T. gigantea leaves (P>0.05) but intakes of pellets comprising 100% T. gigantea leaves were significantly lower (P<0.0001). Both CP and soluble protein intakes declined progressively as the percentage of T. gigantea leaves in the pellets increased. While level of T. gigantea leaves in pellets fed to lambs did not generally affect total intakes of pellets, grass, or grass+pellets, animal performance on these various rations cannot be assumed to be similar until longer-term feeding studies have been performed, as reduced protein and energy concentrations in the pellets could significantly lower weight gains as level of leaf in the pellets increased.

Uso de sensores remotos en la determinación del forraje disponible de Urochloa humidicola cv. Llanero bajo pastoreo en la Altillanura colombiana

Modernization of pastoral systems based on the use of Urochloa species in the Colombian Eastern Llanos need the use of remote sensing techniques from satellite platforms to estimate amount of offered forage. In the Carimagua Research Centre of the Colombian Corporation for Agricultural Research (Agrosavia), an Urochloa humidicola cv. Llanero pasture was evaluated using Landsat 8 and Sentinel 2A images. The NDVI, SAVI, EVI y GNDVI vegetation indexes determined by using the blue, green, red and near infrared bands; and the results analyzed with the R free software, to relate those indexes with forage availability field measures taken during the dry season. Forage availability ranged between 290 and 656 kg DM ha-1 and the vegetation indexes for the Landsat 8 and Sentinel 2A sensors were: NDVI = 0.67 (±0.037) and 0.69 (±0.061); SAVI = 0.48 (±0.048) and 0.41 (±0.046); EVI = 0.70 (±0.052) and 0.41 (±0.047); y GNDVI = 0.60 (±0.028) and 0.70 (±0.034), respectively. The relationships between vegetation indexes and forage availability were linear. The Coefficient of Determination (R2= 0.56‒0.72) and the Mean Square Error (MSR =63.95‒80.16) of the prediction equations were used. In conclusion, under the conditions of the study, the EVI for Landsat 8 and NDVI for Sentinel 2A were considered adequate for estimating forage availability of Urochloa humidicola cv. Llanero.

Biomass production and nutritional properties of promising genotypes of Tithonia diversifolia (Hemsl.) A. Gray under different environments

Tithonia diversifolia is a shrub with excellent forage characteristics that has shown a wide genetic and phenotypic diversity. The objective of this study was to determine the biomass production and nutritional quality of seven genotypes of T. diversifolia with outstanding characteristics for ruminant nutrition, to analyze the Genotype x Environment (GxE) interaction of biomass production and to compare the performance of these genotypes with grasses offered normally in tropical conditions. For the GxE interaction the AMMI and SREG models were used, and evaluations were made in three environments. In the GxE analysis, the interaction was significant and effects of the environment on biomass productivity were observed with differences between genotypes (p <0.05). In the three environments, the chemical composition was adequate to be offered to ruminants. It is worth noting the high content of crude protein (28.89 g/100 g of dry matter - DM), the low fiber content (30.95 g of neutral detergent fiber - NDF/100 g of DM) and the high percentages of in vitrodegradation of DM for all the genotypes. It is possible to conclude that there are superior genotypes of T. diversifolia with the ability to have good productive and adaptive performance for high-altitude and low-altitude zones with low fertility soils.

Canopy characteristics of ‘Mavuno’ hybrid brachiariagrass and ‘Marandu’ palisadegrass harvested at different harvest intensities

‘Mavuno’ is a newly released brachiariagrass (Urochloa hybrid) cultivar with limited information available in the literature. The objective of this study was to compare forage characteristics of this cultivar and ‘Marandu’ palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster cv. Marandu] harvested at 2 different stubble heights during 2 growing seasons (January‒April). The study was conducted in Araguaína, TO, Brazil in 2017 and 2018. Treatments were the factorial arrangement of 2 brachiariagrass cultivars, Mavuno and Marandu, harvested at 2 harvest intensities, 5 and 15 cm stubble height, distributed in a randomized complete block design with 4 replicates. Response variables were canopy height, forage accumulation, proportion of leaf, stem and dead material, and concentration of crude protein (CP) and in vitro digestible organic matter (IVDOM). Mavuno and Marandu did not differ (P>0.05) in forage accumulation (mean = 3,800 kg DM/ha/harvest) and IVDOM concentration (mean = 637 g/kg); however, Mavuno had lower CP concentration (101 vs. 110 g/kg), greater proportion of stems (16 vs. 13%) and less dead material (4 vs. 6%) than Marandu (P<0.05). Harvesting at 5 cm stubble height rather than 15 cm increased herbage accumulation per harvest (4,100 vs. 3,500 kg DM/ha) with decreased proportion of leaves (77 vs. 84%) and CP concentration (101 vs. 115 g/kg) (P<0.05). Our data suggest that Mavuno is a useful addition to the range of brachiaria grass cultivars for sowing in tropical regions and further studies are needed to evaluate the long-term persistence of Mavuno under different management practices in a range of environmental situations. While harvesting at 5 cm stubble height rather than 15 cm increased forage accumulation but reduced CP concentration, regardless of cultivar, longer-term effects on the stability of these pastures with these harvest frequencies and heights are open to question and studies should be continued for longer periods to assess longevity of stands under the 2 management strategies. Applying maintenance fertilizer during the growing season might have prevented the marked decline in dry matter accumulation as the season advanced and this hypothesis should be tested.

What drives the adoption of fodder innovation(s) in a smallholder dairy production system? Evidence from a cross-sectional study of dairy farmers in India

The study in India involving 384 households found that 42.7% of dairy farmers adopted new forage varieties when varieties were released. The farmer’s resources, their caste, access to markets for milk and price received for milk had positive effects on the decision to adopt. Management of farms by women had negative effects on the adoption decision. Increased forage yield and ease of propagation and establishment were important reasons for adoption of varieties, e.g. the relative advantage of pearl millet × Napier grass (Cenchrus americanus × C. purpureus) vs. hedge lucerne (Desmanthus virgatus). Thus, researchers need to address these issues when developing new germplasm, if farmers are to readily adopt new varieties, especially in the case of resource-poor farmers.

Genetic diversity and population structure of Heteropogon contortus L. germplasm collected from diverse agro-climatic regions in India and development of a core germplasm set

Heteropogon contortus, an important constituent of major grasslands of India, Australia and many countries in Africa, Asia and the Americas, is important for pasture and grassland productivity. Hence genetic improvement of the grass needs attention. A genetic variability study, including development of a core subset, was carried out by evaluating 235 accessions collected from different agro-ecological zones of India. The study, based on 16 metric and 14 non-metric traits along with 8 nutritional parameters, indicated that considerable genetic variability existed among the germplasm and selection could result in identification of suitable types for target environments. Clustering and subclustering was performed to select 35 accessions to form a core subset. The statistical analysis indicated that the core subset captured almost all the variability present in the entire germplasm. The study will help researchers to focus future studies on this core subset in developing genetic improvement programs.