Japanese Journal of Grassland Science

Show abstractHide abstract

Monitoring of the spatial distribution of vegetation characteristics (e.g., forage yield and quality, botanical composition) using aerial remote sensing would be useful for the management and utilization of grasslands. The present study assessed the potential application of remotely sensed hyperspectral data (observed by an AISA Eagle hyperspectral imaging sensor on-boarded a Cessna plane) to grassland management. Specifically, hyperspectral data were used to identify plant species and estimate forage yield, quality, and other grassland vegetation characteristics. Cluster analysis of the hyperspectral data extracted from the images revealed that the plots could be classified into four groups. Principal component analysis of the hyperspectral data accentuated the hyperspectral signal of the near-infrared region as the first principal component. Broad-leaved dock (Rumex obtusifolius L.) was found in the group A classified based on the cluster analysis with the strongest hyperspectral signal in the near-infrared region. However, grass species in the other three groups (B, C, D) classified based on the cluster analysis could not be distinguished using the hyperspectral data. The present results suggest that hyperspectral data in the near-infrared region were effective for distinguishing broadleaved dock in a mixed sward. In addition, the linear discriminant function of hyperspectral data could distinguish the existence of broad-leaved dock at a correct answer rate of not less than 69%.

View full abstract

Download PDF (9277K)

In this study, we established the calibration equation for determining the feed composition and antioxidant activity of powdered and non-powdered sorghum grain. The results showed that near-infrared reflectance (NIR) analysis of powdered grain enabled the rough prediction of the concent-rations of crude protein (CP), crude fat (EE), acid detergent fiber (ADFom), neutral detergent fiber (aNDFom), and tannin, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, with computation of the validation correlation and standard deviation/square error of prediction values (RPD). These values were determined to be as follows: CP, 0.87 and 2.48 ; EE, 0.85 and 2.53 ; ADFom, 0.86 and 2.63 ; aNDFom, 0.69 and 1.54 ; tannin content, 0.90 and 2.95 ; and DPPH radical-scavenging activity, 0.87 and 2.63. Furthermore, the results for NIR analysis of non-powdered grain were as follows : CP, 0.60 and 1.57 ; EE, 0.61 and 1.60 ; ADFom, 0.66 and 1.66 ; aNDFom, 0.57 and 1.46 ; tannin content, 0.89 and 2.92 ; and DPPH radical-scavenging activity, 0.87 and 2.72. These results indicate that the concentrations of CP, EE, ADFom, aNDFom, and tannin, and DPPH radical-scavenging activity in powdered sorghum grain as well as the tannin content and DPPH radical-scavenging activity in non-powdered sorghum grain were good enough for rough screening by using NIR techniques.

View full abstract

This paper describes ammonium sulfate (ReAS) that was recovered from livestock manure compost using ammonia-collecting equipment, and was subsequently used as fertilizer for forage and edible rice. We produced ReAS paste fertilizer (RePa) from ReAS. The cultivation trial involved the rice varieties Fukuhibiki, Bekoaoba and Tsuyahime, which received a basal dressing (5 kg N/10a) and topdressings (3 kg N/10a, 2 times). We compared four types of basal dressing, each containing one of the following: conventional chemical fertilizer (CoF), conventional paste fertilizer (CoPa), ReAS, or RePa. Paste fertilizers were applied to the side row soil, whereas the others were applied on the soil surface. The topdressing was composed of either ReAS or conventional ammonium sulfate. The inclusion of CoPa or RePa fertilizer in the basal dressing resulted in an increase in leaf color and in the number of stems compared with the other two treatments, and improved the early-stage growth of rice. The weight of the whole tops at harvest and the crude protein (CP) content of the brown rice grown using ReAS basal dressing were similar to those obtained using the CoF basal dressing. These results indicate that the basal dressing containing RePa improved the early-stage growth of rice when using side row application. Investigations of the time and rate of topdressing application combined with ReAS basal dressing may enable ReAS to contribute to the improvement of rice yield and CP content.

View full abstract

Register with J-STAGE for free!