The field experiments were conducted for two consecutive rabi seasons (November –March) of 2017–18 and 2018–19 at the Wet land farm of S.V. Agricultural College, Tirupati to calibrate leaf colour chart (LCC) for increasing growth yield, nitrogen uptake under varied plant density to establish and evaluate threshold leaf colour greenness as a guide for in-season need based fertilizer N in maize. Research results indicated that the planting density, nitrogen levels and LCC threshold values significantly influenced all the growth and yield attributes, yield and nitrogen uptake. Plant height, days required to 50% tasselling and silking, cob yield, harvest index and nitrogen uptake increased significantly with increase in plant density i.e., 1,11,111 plants ha-1 with application of fertilizer nitrogen at higher dose i.e. 40 kg ha-1 and by using higher LCC threshold value (LCC 5) in different splits. Whereas, leaf area planr-1, cob girth, number of kernels rows cob-1 and number of kernels cob-1 was lessened significantly with increase in planting density, however it was increased with application of nitrogen at higher rate i.e., 40 kg ha-1 by using higher LCC threshold value (LCC 5) at various splits. Eventually, experimental results manifested that, fine-tuning of N dose and time of application by number of splits which synchronize the crop demand was the best management strategy for sustainable crop growth, production and productivity of maize.

Conservation agriculture (CA) is an innovative approach to managing agricultural ecosystems aimed at achieving sustainable productivity, enhanced profitability, and food security, while conserving resources and protecting the environment. This chapter explores the core principles of CA, focusing on minimum soil disturbance, permanent land cover, and crop rotation, which together significantly improve soil health by enhancing its physical, chemical, and biological properties. Through global and Indian research, CA practices have been shown to improve soil structure, boost natural resource availability, and enhance nutrient cycling and biodiversity. In addition to its environmental benefits, CA plays a key role in mitigating climate change by sequestering carbon and reducing greenhouse gas emissions. The chapter discusses the broader economic, environmental, and social benefits of CA, including its contribution to sustainability and resilience. Practical applications, such as site-specific strategies, appropriate equipment, and farmer training programs, demonstrate CA’s potential. However, challenges remain, particularly lower yields for staple crops and higher labor demands. Looking ahead, CA presents significant opportunities for innovation and development. The chapter concludes by underscoring CA’s crucial role in promoting soil health, enhancing climate resilience, and establishing sustainable food systems, while emphasizing the need for continuous organizational support and strategic alignment for successful implementation.

Efficient nitrogen management is critical to improving maize (Zea mays L.) productivity and sustainability under rainfed conditions, where excessive or untimely N use can result in environmental degradation and low nitrogen use efficiency (NUE). Two years of field studies were conducted during consecutive Rabi seasons (2017-18 and 2018-19) at the wetland Farm of S.V. Agricultural College, Tirupati, to calibrate the lead colour chart (LCC) for increasing grain yield, NUE and nutrient uptake under varied planting densities. The study intended to establish threshold leaf greenness values as practical guides for in-season, need based nitrogen top dressing in maize. A split-split plot design was used with three planting densities (66666, 83333 and 111111 plants ha-1), three nitrogen levels (30, 35 and 40 kg N ha-1) and three LCC thresholds (4, 4.5 and 5). Results showed that highest planting density (111111 plants ha-1) combined with 40 kg N ha-1 applied in splits based on LCC 5 significantly improved plant growth parameters, chlorophyll content, dry matter accumulation and kernel yield (5.36 t ha-1), along with enhanced nitrogen uptake (114.1 kg ha-1) and NUE (31.4 kg grain per kg N). Regression analysis revealed that dry weight (R² = 0.96), LAI (R² = 0.84) and NUE (R² = 0.70) were the strongest predictors of yield. LCC based nitrogen scheduling synchronized N supply with crop demand, minimized losses and improved soil N balance. These findings validate that LCC is an effective, ow cost tool for enhancing maize productivity and nutrient efficient under rainfed conditions.

Abiotic stresses like extreme temperatures, drought, salinity, flood and heavy metals pose serious challenges to global agriculture, resulting in decreased productivity, food insecurity and economic losses. Nanotechnology is now recognised as a radical approach in agricultural science, providing promising solutions to mitigate the adverse impacts of abiotic stressors on plant growth and development. Nanoparticles (NPs) have drawn attention for their potential to address these challenges by improving resource use efficiency, reducing pollution, preventing diseases and promoting sustainability, number of tactics meant to improve crop productivity and quality, reduce nutritional deficiencies and increase stress tolerance. Because of their special characteristics, NPs can act as potent sensors and alter vital physiological and biochemical functions in plants. They also provide novel ways for plants to adjust to shifting environmental circumstances, increasing resilience. Since drought stress impairs nutrient transport and growth and impacts all phases of plant development, it stands out as a serious danger to global food security. The increased activity of antioxidant enzymes, which are essential for preserving cellular integrity and redox equilibrium, is frequently linked to this mitigation. Nano-biotechnology is a viable way to address a number of biotic and abiotic variables limiting output in areas like India, where raising agricultural productivity is essential to supporting a sizable population. Nano-biotechnology has the ability to transform plant growth regulation and stress reduction in agriculture by effectively regulating drought stress by the application of appropriate NP concentrations. This would ensure increased output across a variety of crops.

The impact of climate change presents an opportunity for orphan crops like millet to contribute to sustainable food systems. A prime example of an orphan crop with special traits and the potential to develop climate-smart agriculture is Barnyard millet (BYM). Alkaloids, steroids, polysaccharides, glycosides, tannins, phenols, dietary lignans and flavonoids are just a few of the antioxidants that are abundant in BYM. BYM’s antioxidant potential, prebiotic status, anti-inflammatory, hypoglycemic, antibacterial and anticancerous properties help it to combat a myriad of diseases. The antinutritional compounds present in BYM such phytic acid, tannins, polyphenols, and amylase inhibitors limit the absorption of minerals because they form complexes with dietary minerals like calcium, zinc, magnesium, and iron and make them inaccessible for absorption. Various processing methods like dehulling, soaking, heating, gamma irradiation, cold plasma processing, fermentation might enhance the nutritional and technological functional qualities of BYM. The bioactives in BYM can improve their bioavailability, in vitro digestibility, efficiency, structural modification and stability by biological processing techniques such as germination and fermentation employing microbial strains. BYM straw’s high cellulose and hemicellulose percentage makes C5 and C6 sugars accessible for bioconversion into bioethanol.

Agrochemicals had enabled more than double the food production over the past century and the continued need to feed a growing global population remained the basis for the widespread application of pesticides and fertilisers. Asia alone consumed over half of all pesticides manufactured worldwide. Population growth over the 20th century was highly correlated with increased food production, many of which had relied upon pesticide use. Agriculture provided 70 % of employment in India and hence formed the prime sector of the country's economy with around one-third of agricultural output being dependent on the use of pesticides. Crop production would drastically have come down without the use of pesticides. The critical question was that liberal use of pesticides posed acute environmental and public health risks, where improper and unregulated application left soil, water and food systems contaminated. With increasing food production, there was an urgent need to minimize toxic contaminants and enhance food quality. Bio-pesticides had emerged as a promising alternative to chemical pesticides in supporting sustainable agricultural development while reducing pollution. Another growing development in India was in bio-pesticides, an effective alternative to chemical options. Organic residues for the improvement of soil health could have been another cost-effective and sustainable means of reducing pesticide pollution. However, all such measures were pointless in the absence of a clear understanding of the interplay between pesticides and soil properties further governing their fate and transport in the ecosystem.