B. L. Mina

Effect of organic manures and integrated nutrient management on yield potential of bell pepper (Capsicum annuum) varieties and on soil properties

A field experiment was conducted during the summer season of 2005 and 2006 at Almora (Indian Himalayas) to evaluate the comparative performance of five varieties of bell pepper (Capsicum annuum L.) and changes in soil properties under organic and integrated nutrient management (INM) systems. The number of fruits plant−1 and fruit yield was significantly higher under INM compared with organic nutrient supply. The yield reduction in the latter was 22.1% in 2005 and 21.7% in 2006 compared with INM. Among the bell pepper varieties, ‘US Agri 181’ produced significantly higher fruit yield (25.42 mg ha−1 in 2005 and 28.82 mg ha−1 in 2006) compared with other varieties. The soil pH, organic carbon, and microbial activities in terms of urease, dehydrogenase and alkaline phosphatase were higher in the plots treated with organic manures alone compared to INM. The latter, however, recorded higher N, P, and K contents in soil. The gross margin and benefit:cost (B:C) ratio were higher under INM compared with organic nutrient supply. ‘US Agri 181’ gave the highest net returns followed by ‘Aishwarya’ and ‘California Wonder’. However, the latter recorded the highest B:C ratio (9.2) compared with other varieties. We conclude that at least 25–50% price premium for organic bell pepper may be required to offset the higher cost of cultivation and low yields under organic production system. Among the bell pepper varieties, ‘US Agri 181’ was the best variety as it yielded highest followed by ‘Aishwarya’.

Expression of Soil Chemical and Biological Behavior on Nutritional Quality of Aromatic Rice as Influenced by Organic and Mineral Fertilization

The aim of the study was to evaluate changes in the yield and nutritional characteristics of aromatic rice as influenced by organic versus mineral fertilization. Aromatic rice was grown on four levels of cattle manure (CM; 5, 10, 15, and 20 Mg ha−1). Other treatments were equivalent amounts of nitrogen (N), phosphorus (P), and potassium (K) in different levels of manure fertilizer and mineral fertilizer. After 6 years of cropping, organically managed plots were superior to mineral-fertilized plots in terms of grain yields of rice at 5, 10, and 15 Mg ha−1. Cattle manure at 20 Mg ha−1 and its equivalent NPK through mineral-fertilizer treatment provided 41.1% and 37.9% increases in average grain yield (5.2 and 5.1 Mg ha−1) over the unamended control. Protein content was greater in mineral-fertilized rice grains at all levels of CM. Soil dehydrogenase, β-glucosidae, urease, and acid phosphatase activities were greater in soil treated with CM than soil treated with the corresponding mineral fertilizer at all levels. There was buildup of soil-available N, K, and iron (Fe) in soils treated with CM. Grain hardness increased with increasing rates of nutrient application for both mineral-fertilized and organically grown rice; in contrast, amylose content was lower in treatments receiving more nutrients, irrespective of nutrient sources. In terms of functional property, phenol content in rice grain increased with increasing nutrient supply. Potassium and Fe contents were more in CM-treated rice than in mineral-fertilized treatments at greater rates of application. Results suggest that after building up the soil nutrient status, comparable yield and better nutritional and functional qualities of rice can be achieved in organically managed soils than in mineral-fertilized soils.

Yield potential of garden pea (Pisum sativum L.) varieties, and soil properties under organic and integrated nutrient management systems

The identification of suitable crop varieties that respond best to organic management is the key to achieving better crop yields. A field experiment was conducted during the winter season of 2005–2006 and 2006–2007 at Almora (Indian Himalayas) to evaluate the performance of five varieties of garden pea (Pisum sativum L.) and changes in the soil properties under organic and integrated nutrient management (INM) systems. The yield reduction under organic management was 14.4% in 2005–2006 and 10.1% in 2006–2007 compared with INM. Among the garden pea varieties ‘Vivek Matar 9’, ‘Vivek Matar 8’ and ‘Azad pea 1’ produced similar but significantly higher pod yield compared to other varieties. The soil pH, organic carbon, and microbial activities in terms of dehydrogenase and phosphatase (acid and alkaline) were higher in the plots under organic management compared to INM. The latter, however, had higher activity of urease, and N, P, and K contents in soil. We conclude that at least 15–20% price premium for organic garden pea may be required to offset the higher cost of cultivation and low yields under organic production system. Among the garden pea varieties, ‘Azad pea 1’, ‘Vivek Matar 8’ and ‘Vivek Matar 9’ were found suitable for organic cultivation.

Optimization of Farmyard Manure to Substitute Mineral Fertilizer for Sustainable Productivity and Higher Carbon Sequestration Potential and Profitability under Gardenpea-French Bean Cropping System in the Indian Himalayas

Carbon sequestration potential (CSP) and sustainability of gardenpea-french bean cropping system was assessed with farmyard manure (FYM) application vis-à-vis mineral fertilization as recommended NPK (NPK) and integrated nutrient management practices (INM) after six years’ cropping in Indian Himalayas. Application of 20 tons FYM ha−1 provided highest CSP (0.527 Mg C ha−1 year−1) in soil and sustainability index. With the help of quadratic equations, it was estimated that maximum profit (optimum yield) and turn over of invested money could be achieved with application of 20.0 and 15.6 t FYM ha−1, respectively. Application of 5.9 and 8.9 tons FYM ha−1 would substitute NPK and INM, respectively. Pod number plant−1 was the most important yield-contributing attribute as found from principal component analysis. Pod yield could be modelled through multiple linear equation with help of yield attributes.

Effects of Organic Amendments on Productivity and Profitability of Bell Pepper–French Bean–Garden Pea System and on Soil Properties during Transition to Organic Production

A transition period of at least 2 years is required for annual crops before the produce may be certified as organically grown. There is a need to better understand the various management options for a smooth transition from conventional to organic production. The purpose of this study was to evaluate the effects of different organic amendments and biofertilizers (BFs) on productivity and profitability of a bell pepper–french bean–garden pea system as well as soil fertility and enzymatic activities during conversion to organic production. For this, the following six treatments were established in fixed plots: composted farmyard manure (FYMC, T1); vermicompost (VC, T2); poultry manure (PM, T3) along with biofertilizers (BF) [Rhizobium/Azotobacter + phosphorus solubilizing bacteria (Pseudomonas striata)]; mix of three amendments (FYMC + PM + VC + BF, T4); integrated nutrient management (FYMC + NPK, T5); and unamended control (T6). The yields of bell pepper and french bean under organic nutrient management were markedly lower (25.2–45.9% and 29.5–46.2%, respectively) than with the integrated nutrient management (INM). Among the organic treatments, T4 and T1 produced greater yields of both bell pepper (27.96 Mg ha−1) and french bean (3.87 Mg ha−1) compared with other treatments. In garden pea, however, T4 gave the greatest pod yield (7.27 Mg ha−1) and was significantly superior to other treatments except T5 and T1. The latter treatment resulted in the lowest soil bulk density (1.19 Mg m−3) compared with other treatments. Similarly, soil organic C was significantly greater in all the treatments (1.21–1.30%) except T2 compared to T6 (1.06%). Plots under INM, however, had greater levels of available nitrogen–phosphorus–potassium (NPK) than those under organic amendments. T1 plots showed greater dehydrogenase and acid phosphatase activities compared with other treatments. However, T4 and T5 plots had greater activities of β-glucosidase and urease activities, respectively. The cost of cultivation was greater under organic nutrient management (except T2) compared with INM. The latter treatment gave greater gross margin and benefit/cost (B/C) ratio for all vegetables, except that T2 gave greater B/C ratio in garden pea compared with other treatments. We conclude that T1 and T4 were more suitable for enhancing the productivity of bell pepper–french bean–garden pea system, through improved soil properties, during transition to organic production.

Evaluation of mulching, stale seedbed, hand weeding and hoeing for weed control in organic garden pea (Pisum sativum sub sp. Hortens L.)

Weeds are often recognized as the principal biotic constraint to organic crop production. Development of suitable weed control measures is, therefore, a prerequisite for profitable organic farming. A field experiment was conducted during the winter season of 2003–2004 and 2004–2005 in the Indian Himalayas to evaluate the effect of mulching, stale seedbed, hand weeding and hoeing on weeds and yield of organic garden pea (Pisum sativum sub sp. Hortens L.). The weed population ranged from 249–477 m−2, and Polygonum plebejum L. (34%), Melilotus indica L. (31%) and Avena ludoviciana Dur. (17%) were the predominant weeds in the experimental field. Season long weed-crop competition reduced the green pod yield of garden pea by 74% in 2003–2004 and 93% in 2004–2005. All the weed control treatments significantly reduced the population and biomass of weeds resulting in significant increase in green pod yield of garden pea compared to unweeded control. The highest weed control efficiency (84% reduction in weed biomass) was achieved with hand weeding 30 and 60 days after sowing (DAS) closely followed by stale seedbed coupled with one hand weeding (77%). Both these treatments produced significantly higher green pod yield compared to other treatments in both the years. In 2003–2004, hand weeding (30 and 60 DAS) recorded the highest gross margin (Indian Rupees 115,400 ha−1) closely followed by stale seedbed coupled with one hand weeding (Indian Rupees 109,700 ha−1). In the second year, however, the latter treatment gave the highest gross margin (Indian Rupees 56,900 ha−1) compared to other treatments.