No abstract

Driven by the possibility of precise transformational change in nutrient-enrichment technology to meet global food demand, advanced nutrient delivery strategies have emerged to pave the path toward success for nutrient enrichment in edible parts of crops through bioderived nanocarriers with increased productivity. Slow and controlled release of nutrient carrier materials influences the nutrient delivery rate in soil and in the edible parts of crops with a sluggish nutrient delivery to enhance their availability in roots by minimizing nutrient loss. With a limited understanding of the nutrient delivery mechanism in soil and the edible parts of crops, it is envisaged to introduce nutrient-enrichment technology for nutrient delivery that minimizes environmental impact due to its biodegradable nature. This article attempts to analyze the possible role of the cellulose matrix for nutrient release and the role of cellulose nanocomposites and nanofibers. We have proposed a few cellulose derived biofortificant materials as nutrient carriers, such as (1) nanofibers, (2) polymer–nanocellulose–clay composites, (3) silk-fibroin derived nanocarriers, and (4) carboxymethyl cellulose. An effort is undertaken to describe the research need by linking a biopolymer derived nanocarrier for crop growth regulation and experimental nitrogen release analysis. We have finally provided a perspective on cellulose nanofibers (CNFs) for microcage based nutrient loading ability. This article aims to explain why biopolymer derived nutrient carriers are the alternative candidate for alleviating nutrient deficiency challenges which are involved in focusing the nutrient delivery profile of biopolymers and promising biofortification of crops.

Agroforestry systems (AFS) and practices followed in India are highly diverse due to varied climatic conditions ranging from temperate to humid tropics. The estimated area under AFS in India is 13.75 million ha with the highest concentration being in the states of Uttar Pradesh (1.86 million ha), followed by Maharashtra (1.61 million ha), Rajasthan (1.55 million ha) and Andhra Pradesh (1.17 million ha). There are many forms of agroforestry practice in India ranging from intensified simple systems of monoculture, such as block plantations and boundary planting, to far more diverse and complex systems, such as home gardens. As a result, the biomass production and carbon sequestration potential of AFS are highly variable across different agro-climatic zones of India. Studies pertaining to the assessment of biomass and carbon storage in different agroforestry systems in the Indian sub-continent are scanty and most of these studies have reported region and system specific carbon stocks. However, while biomass and carbon stock data from different AFS at national scale has been scanty hitherto, such information is essential for national accounting, reporting of C sinks and sources, as well as for realizing the benefits of carbon credit to farmers engaged in tree-based production activities. Therefore, the objective of this study was to collate and synthesize the existing information on biomass carbon and SOC stocks associated with agroforestry practices across agro-climatic zones of India. The results revealed considerable variation in biomass and carbon stocks among AFS, as well as between different agro-climatic zones. Higher total biomass (>200 Mg ha−1) was observed in the humid tropics of India which are prevalent in southern and northeastern regions, while lower total biomass (<50 Mg ha−1) was reported from Indo-Gangetic, western and central India. Total biomass carbon varied in the range of 1.84 to 131 Mg ha−1 in the agrihorticulture systems of western and central India and the coffee agroforests of southern peninsular India. Similarly, soil organic carbon (SOC) ranged between 12.26–170.43 Mg ha−1, with the highest SOC in the coffee agroforests of southern India and the lowest in the agrisilviculture systems of western India. The AFS which recorded relatively higher SOC included plantation crop-based practices of southern, eastern and northeastern India, followed by the agrihorticulture and agrisilviculture systems of the northern Himalayas. The meta-analysis indicated that the growth and nature of different agroforestry tree species is the key factor affecting the carbon storage capacity of an agroforestry system. The baseline data obtained across various regions could be useful for devising policies on carbon trading or financing for agroforestry.

Wasteland is defined in various ways by different agencies. However, in general it represents degraded, unused, and uncultivated lands. These lands have utilized in recent past to bridge the gap between demand and supply of food, fodder, timber, and also for resource conservation. Area under mines in the country is about 0.19 m ha and ravine lands 4 m ha. Though mining is important for industrial growth, it also has negative impact on the environment and renders the land unproductive. Rehabilitation of such degraded areas requires systematic and scientific approach which includes proper survey, choice of species, and techniques for establishment of plant species. Rehabilitation of ravine lands involves treatment of table and marginal lands contributing runoff to the gullies and proper gullies/ravines on watershed basis. It requires an integrated approach of using gullies according to land capability classes, soil, and water conservation measures and putting land under permanent vegetation cover involving, afforestation, agroforestry, horticulture, pasture, and energy plantations. Watershed development has become the major intervention for managing natural resources. Majority of the watersheds in the country are degraded and suffer from poor productivity, biotic pressure, acute fodder shortage, poor livestock productivity, poverty, water scarcity, and poor infrastructure. A multitier ridge to valley sequenced approach is required to treat the watersheds for enhancing productivity and resource conservation. This

Shivalik region is sandwiched between Himalayan ecosystem and Indo-Gangetic plains in northwestern India. However, its area is reported to range from 2.14 to 8.00 m ha in northwestern India by different workers. Based on geology and physiography, we demarcated the Shivalik region (3.33 mha), covering hills (1.79 mha) and its piedmont plains or foot hills (1.54 m ha) in the states of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Punjab, Haryana, Uttar Pradesh and union territory of Chandigarh at an elevation ranging from 217 to 2332 m above MSL. The delineated map showing Shivalik region will be useful in conserving the natural resources of the region without any dispute over its location and area.