Precise nutrient management for enhancing crop yield is possible through delineating soil management zones. Generally, the fertilizer recommendations followed use a blanket application for a larger area without considering the soil spatial variability. This may lead to low fertilizer application in pockets of less nutrient content and vice versa. Therefore, this study aims to develop soil management zones (MZs) adopting geostatistical and fuzzy clustering techniques in the Alwarthirunagiri block of the Thoothukudi district in Southern India. One hundred and seventy-one surface samples were collected from a study area of 2760 ha. The collected soils were processed and characterized by available macronutrients and micronutrients. The coefficient of variation of the soils varied from low (9.72%) to high (74.60%). Ordinary kriging and semivariogram analysis showed wide variation in the soil characteristics within the study site, with a spatial dependence ranging from moderate to strong. Four management zones were demarcated based on fuzzy performance index and normalized classification entropy using PCA and fuzzy K-means clustering. The study results indicated that the soil properties differed significantly under different management zones and provided potential site-specific fertilizer management options. The management zone map could be useful to the farmers to adopt precise management of nutrients for different zones.

Soil health and environmental degradation are some of the major challenges to the sustainable production of organic rice cultivation. The study utilized farming systems components like Azolla, fish and duck as nutrient sources in rice cultivation during late samba 2022-23 and 2023-24 at Tamil Nadu Rice Research Institute, Aduthurai, Tamil Nadu. The experiments were conducted with eleven treatments replicated thrice in a randomized block design, the treatments included green manure, fish, Azolla, duck and liquid bio fertilizers and their combinations with nano urea foliar spray were compared with RDF. The results demonstrated a significant positive impact of integrating farming system components on rice growth and productivity. GM- Rice + fish + Azolla + duck (PSB+KSB+ZSB) along with nano urea foliar spray (0.4 %) recorded the maximum growth and physiological parameters over other treatments. Similar results were also observed in yield attributes of rice viz., the number of panicles (457 m-2), panicle length (31.26 cm), panicle weight (3.94 g), and filled grains panicle-1 (331.5). The higher grain (6.06 t ha-1), straw yield (7.81 t ha-1), rice equivalent yield (REY) (22.55 t ha-1), system productivity (61.79 kg ha-1 day-1), sustainable yield index (0.881) and relative production efficiency (440.3 %) of rice were recorded in GM- Rice + fish + Azolla + duck (PSB+KSB+ZSB) along with nano urea foliar spray (0.4 %). Additionally, lower pest incidences and higher insect pest control efficiency, richness, diversity and evenness indices were observed in green manure, Azolla, fish and duck-adopted treatments. The findings of experiments revealed that the inclusion of integrated farming system components significantly improved the yield and reduced pest incidences in rice.

Talinum fruticosum (L.) Juss. is an underutilized plant which is distributed across world. It survives under varying soil types such as deep fertile soil, shallow rocky soil, salt affected soils, etc. Waterleaf occurs from sea level to 1000 m above MSL. Tolerance to drought is added advantage but, yield decreases with increasing water stress. It moderately tolerates salinity and sodicity of both soil and water. This plant can be exploited as plant for phytoremediation as it is capable to accumulate heavy metals, pollutants and minerals. It has significant potential to use it as fodder for cattle considering green biomass and nutritional composition. This plant can also be used as feed to chickens, rabbits and cattle. It is considered as palatable, leafy vegetable owing to nutritional and medicinal properties though it possess lesser amount of anti-nutritious components such saponin, oxalates and tannins. In view of above facts, waterleaf have the potential to be utilized as leafy vegetable for semiarid and humid conditions, quality green fodder for cattle, feed for rabbits and chicken, remediating polluted soils, reclamation and sustainable utilization of salt affected lands, tolerant plant for poor quality water, suitable to shallow soils besides using it as ornamental plant.

Phosphorus (P) is a crucial limiting nutrient in soils, directly impacting plant growth and yield. Its availability to plants is generally low due to high fixation, poor solubility and slow diffusion rates. Over 80 % of the P applied to soil in agricultural systems becomes fixed as insoluble phosphates, with less than 20 % being utilized by crops. This leads to an accumulation of P in the soil. Continuous farming with fertilization contributes significantly to this P buildup. Research on P budgets shows that the amount of insoluble P in soil far exceeds what crops need, suggesting a significant opportunity to reduce inorganic P fertilization by tapping into these native P reserves. However, the natural solubilization of these reserves is minimal. Improving P solubilization could help unlock this unavailable P for plant use. Phosphate-solubilizing bacteria (PSB) have gained prominence due to their potential to reduce the need for P fertilizers, mitigate environmental pollution and boost agricultural productivity. This review explores the diversity of PSB, the mechanisms they use to solubilize native soil P, their effectiveness in various environmental conditions and their impact on crop productivity and P use efficiency, particularly in rice systems.

India's rich heritage of traditional rice varieties holds immense potential for enhancing nutritional and health security while ensuring sustainable rice productivity amid changing climatic conditions. These indigenous cultivars are naturally rich in essential nutrients, antioxidants and bioactive compounds that contribute to disease prevention and overall well-being. Known for their remarkable adaptability, traditional rice varieties thrive in diverse climates, soil types and growth periods, demonstrating exceptional resilience to extreme weather conditions, pests and various environmental stresses. Additionally, these rice cultivars play a crucial role in preserving biodiversity and supporting sustainable farming practices. This review highlights the immense significance of folk rice cultivars of India in ensuring long-term nutritional security, improving public health and augmenting the income of rice farmers by offering high-value produce. By integrating these traditional varieties into modern agricultural systems, their unique advantages can be harnessed to address food security concerns while promoting ecological balance and economic sustainability for farming communities across India.

Sunn hemp (Crotalaria juncea L.) is a versatile legume belonging to the family Fabaceae, commonly used as a green manure or cover crop adding benefits to the cropping system. Nowadays, the excessive use of chemical sources of nitrogen to meet the crop demands has led to poor nitrogen use efficiency and significant environmental degradation. Reducing the use of synthetic fertilizers by supplementing them with green manure can minimize these negative impacts without compromising crop requirements. The incorporation of sunn hemp helps to improve the soil structure, water holding capacity, problem soil reclamation and increases nitrogen availability to the succeeding crop. Besides being used as a green manure crop, it is also grown as a fibre crop, due to the soft, strong and slightly lignified nature of its fibre. Synthetic fibres in blends are deleterious to the planet, requiring the search for natural and sustainable alternatives. The value of ecologically friendly resources has been increasing. Sunn hemp fibre is an underutilized lignocellulose fibre with a wide range of applications and an excellent substitute for synthetic fibres as it has natural characteristics such as high mechanical strength, low density, low cost, easy availability, biodegradability, etc. It is a fast-growing legume with high biomass, increased accumulation of nitrogen, weed suppressor, nematode controller and generates bioproducts viz., biofuel and bioenergy. The role of sunn hemp in nitrogen mineralization, their fibre properties and versatility in day-to-day activity make it a promising crop for the present and future generations. This review article presents the various uses of sunn hemp through past years of research.