**4. Agro-botanical superiority and multipurpose utilization of underutilized grasses**

Many of underutilized grasses have been recognized to be resilient to numerous abiotic stresses including heat stress, drought, water logging, salinity, heavy metal toxicity etc. These also offer multiple uses including food, renewable fuel, feed, fiber and contributions to ecosystem services. A variety of underutilized grasses including reed canary grass (*Phalaris arundinacea* L.), miscanthus (Miscanthus × giganteus Greef et Deuter), giant reed (*Arundo donax* L.), switchgrass (*Panicum virgatum* L.) etc. have the potential to serve as an excellent raw material source for modern biorefineries for producing numerous high-added value products including nutrient supplements, biopharmaceuticals, biopolymers, biomaterials for mulching, building infrastructure, phonic insulating, biodegradable products for utilization in animal bedding and gardening, energy carriers including advanced biofuels, many by-products including green chemistry products and soil organic fertilizers, along with a bunch of ecosystem services such as soil erosion and degradation protection, C-sequestration, restoration and preservation degraded and contaminated soils. It has indicated that underutilized grasses have the potential to thrive well under variable agroenvironmental conditions including degraded and marginal lands without being in competition with food crops. Besides higher environmental sustainability, bio-energy potential has also been recognized as a plus point of underutilized perennial grasses which are established once and provide harvest on a yearly basis over a period of 10–25 years resulting in greenhouse gas balances. The lignocellulosic structure of grass cell walls constitutes one of the critical sustainability characteristics which impart natural resistance against various pests and diseases [13].

Additionally, grasses tend to have higher resource-use efficiency for having C-4 photosynthetic pathway which is characterized by substantially higher solar radiation capture and moisture utilization, along with being lesser nutrient demanding and have potential to conserve nutrients in underground roots during harsh climatic conditions like chilling temperatures during winters. Furthermore, many underutilized grasses by virtue of their vigorous biomass production add crop residues to the soil due to senescence, and thus provide natural mulch for controlling weeds



#### **Table 1.**

*Different underutilized grasses, their geographical presence and perspectives uses under varying farming systems and socio-economic perspectives.*

and release of nutrients from residues after decomposition. Overall, cultivation of high yielding underutilized grasses can potentially multiply land-use-efficiency and higher productivity per unit of area. In addition, there is a great potential to still improve their performances. However, many of underutilized grasses are either undomesticated or are at earlier development stages, while in-depth studies are needed to develop their production technology package. One of the limitations of traditional breeding is the exceptionally lengthy process which might extend for over 15 years involving collection of germplasm, selection of parental lines, selective crossing to achieve desired traits and allowing evaluation cycles for random genetic mutations.

In addition to bio-energy applications of underutilized grasses, there are diversified uses of perennial grasses such as pulping as well as bleaching potential of giant reed for papermaking due to having moderate strength properties along with bleachability characteristics. In addition, miscanthus which is an underutilized grass has proved its potential and feasibility for producing various types of panel boards, building blocks of various infrastructures and medium-density fibreboard having comparable characteristics as that of wood chips. A significant equity between miscanthus and crops straw for animal bedding preparation could be achieved as far as cow comfort in the barnyard is concerned. However, the superiority of this perennial grass over straw has been established owing to higher biomass production potential compared to many cereals such as wheat, rice etc. Moreover, lignocellulosic biomass yielded by underutilized grasses might be processed into diversified products; however, lack of market development has so far hampered wider-scale implementation of the lignocellulosic biorefinery. It may be noted that lignocellulosic biomass currently fetches around 65 € per dry ton [12–14].

Thus, it becomes evident that productivity potential and the ability to generate comparable revenues of underutilized grasses would be the key drivers in farmer's perspectives. It also follows that comprehensive real time data pertaining to yield would be critical in order to provide accurate and reliable information to researchers, growers and entrepreneurs. Moreover, underutilized grasses future will be determined on development of consistent, feasible, farmer's friendly and affordable economic plans encompassing economically profitable plantation size and tailor-designed low-tech and easily accessible processing plants for producing market capturing products. At farm scale, advanced research for developing agronomic packages, designing breeding programs, building post-harvest logistics and bioconversion facilities are fundamental aspects that need thorough attention of researchers and governments for harnessing the potential of underutilized grasses. These will follow production of climate resilient genotypes of underutilized grasses having the potential to thrive well in a wider range of agro-environmental conditions on marginal lands without coming into competition with food crops (see **Table 1**).
