(a) Classify natural resources. Discuss the natural resource management with reference to ecological conservation. (10…

(a) Natural Resources and Ecological Conservation

Natural resources are broadly classified based on renewability into renewable resources (solar radiation, fresh water, biomass) and non-renewable resources (fossil fuels, metallic and non-metallic minerals). Based on origin, they are grouped into biotic resources (forests, wildlife, crops, soil microbes) and abiotic resources (land, rocks, minerals, air).

Natural Resource Management (NRM) aligns human resource utilization with ecological carrying capacity to ensure long-term ecosystem stability. Implementing a ridge-to-valley watershed approach (as under the PMKSY-Watershed Development component) arrests topsoil erosion, enhances in-situ moisture retention, and recharges depleted aquifers. Sustainable management integrates conservation tillage, agro-ecological zoning, and optimal resource cycling to preserve vital ecosystem services such as carbon sequestration, nutrient cycling, and hydrological regulation. Decentralized community participation, exemplified by Joint Forest Management Committees and Water Users Associations, ensures that resource stewardship balances immediate economic livelihoods with the imperative of biodiversity preservation and ecological resilience.

(b) Cropping System vs. Cropping Pattern and Principles

Distinction: Cropping pattern denotes the spatial and temporal arrangement of crops on a specific land area over a given period (e.g., Rice-Wheat or Cotton-Wheat systems). In contrast, a cropping system represents the cropping pattern combined with the complete management regime and bio-physical interactions between crops, soil, water, climate, and available farm inputs over time.

Principles of Cropping System:

1. Resource Use Efficiency: Maximizing the interception of photosynthetically active radiation, rooting depth utilization, and moisture extraction across spatial strata.
2. Biological Compatibility and Complementarity: Selecting crop combinations with non-overlapping peak nutrient demands and positive allelopathic or symbiotic effects, such as cereal-legume intercropping.
3. Sustainability and Soil Health: Enhancing physical, chemical, and biological soil properties through balanced crop rotations and green manuring.
4. Yield Stability and Risk Mitigation: Diversifying crops to buffer against market fluctuations, pest outbreaks, and climate-induced abiotic stresses.
5. Economic Profitability: Optimizing the land equivalent ratio (LER) and net returns per unit of land, water, and labor invested.

(c) Agrisilviculture vs. Agrisilvipasture Systems

Distinction: Agrisilviculture is a two-tier agroforestry system combining agricultural crops with tree species (silviculture) on the same management unit, primarily aimed at food, timber, and fuelwood production on arable lands. Agrisilvipasture is a three-tier integrated system combining agricultural crops, woody perennials (trees/shrubs), and pasture grasses/legumes alongside livestock grazing or stall-feeding, usually implemented on marginal or degraded lands to satisfy food, fodder, and timber requirements simultaneously.

Component Crops and Examples:

• Agrisilviculture: Intercropping Wheat (Triticum aestivum) or Mustard (Brassica juncea) under Poplar (Populus deltoides) or Eucalyptus (Eucalyptus tereticornis) in the irrigated plains of Punjab and Haryana.
• Agrisilvipasture: Cultivating Pearl Millet (Pennisetum glaucum) or Cowpea (Vigna unguiculata) alongside pasture grasses like Anjan grass (Cenchrus ciliaris) or Stylosanthes hamata, under multipurpose tree canopies of Khejri (Prosopis cineraria) or Babul (Acacia nilotica), integrated with sheep or goat rearing in arid and semi-arid Rajasthan.

(d) Forest Policies and Their Aims

• National Forest Policy, 1894: Formulated during the colonial era, its primary aim was state-controlled commercial exploitation of timber for imperial infrastructure (railways and defense), subordinating forest conservation to the expansion of settled agriculture.
• National Forest Policy, 1952: Post-independence policy aimed at meeting vital national defense and industrial raw material needs. It set a national target of maintaining 33% of the total geographical area under forest cover (60% in mountainous tracts) to ensure ecological balance.
• National Forest Policy, 1988: Marked a decisive transition from revenue extraction to conservation-centric governance. Its core aims were environmental stability, preserving genetic diversity, checking soil erosion, and meeting the local fuelwood, fodder, and small timber requirements of tribal communities via Joint Forest Management (JFM).
• Draft National Forest Policy, 2018: Aims at climate change mitigation through enhanced carbon sinks, catchment area treatment, combating human-wildlife conflict, and integrating public-private partnerships (PPP) with community rights for the afforestation of degraded lands.

(e) Weed Control Efficiency (WCE)

Weed Control Efficiency (WCE) is the percentage reduction in weed population or weed dry matter accumulation achieved by a given weed control treatment compared to an unweeded control check.

WCE (%) = (W_c - Wₜ)/(W_c) × 100

Where W_c is the weed population in the unweeded check (T₁ = 90), and Wₜ is the weed population in the treatment plot.

Calculations:

• T₂ (Hand weeding): (90 - 55)/90 × 100 = 38.89%
• T₃ (Herbicide A): (90 - 45)/90 × 100 = 50.00%
• T₄ (Herbicide B): (90 - 40)/90 × 100 = 55.56%
• T₅ (Herbicide C): (90 - 50)/90 × 100 = 44.44%

Critical Comment: Herbicide B (T₄) achieved the highest efficacy (55.56%), whereas manual hand weeding (T₂) exhibited the poorest control (38.89%), likely due to late execution or rapid weed flushes. However, exclusive reliance on high-efficacy chemical treatments poses long-term risks, including environmental toxicity, non-target damage to soil biota, herbicide residue carryover, and the selection pressure driving herbicide-resistant weed biotypes. An Integrated Weed Management (IWM) strategy—combining optimized herbicide use with mechanical weeding and cultural suppression—is essential for sustainable and economically viable weed control.