Journal of Tropical Agriculture 

About: Journal of Tropical Agriculture is an academic journal. The journal publishes majorly in the area(s): Population & Crop yield. It has an ISSN identifier of 0971-636X. Over the lifetime, 514 publications have been published receiving 4070 citations.

Soil fertility status, nutrient uptake, and maize (Zea mays L.) yield following biochar and cattle manure application on sandy soils of Lombok, Indonesia.

Abstract: A field study was conducted to evaluate the effects of biochar application on soil fertility status, nutrient uptake, and maize yield in the sandy soils of semiarid Lombok, Indonesia during the rainy season of 2010–2011 and dry season of 2011. Three organic amendments (coconut shell biochar, CSB; cattle dung biochar, CDB; cattle manure, CM, and no organic amendments as control, C) constituted the treatments. Biochar application improved soil fertility status, especially soil organic C, CEC, available P, exchangeable K, Ca, and Mg, and increased nutrient uptake and maize yield. Soil organic C increased from about 0.9% (untreated soil) to about 1.20% (biochar and CM treated). Soils treated with biochar had consistently higher organic C contents, which also remained more stable compared to the soils treated with CM, implying the higher potential of biochar for soil carbon sequestration. The highest maize yield during the rainy season was noted for CM, followed by CDB and CSB (5.98, 5.87, and 5.71 Mg ha–1 respectively). However, yield of the second crop in one-time CM application treatment declined. This was not the case for maize yield on biochar treated soil.

Efficient fertilizer use: the key to food security and better environment.

Abstract: Since the inception of Green Revolution there has been a race for increasing foodgrain (mainly cereals) production using chemical fertilizers in India. However, cereal production in the country increased only five fold, while fertilizer consumption increased 322 times during the 1950–51 to 2007–08 period, implying a very low fertilizer use efficiency. Large scale applications of fertilizer nitrogen (N) have also shown deleterious effects on groundwater quality, especially its nitrate content, which is harmful to health. Furthermore, gaseous losses of N as NH3 and NOx resulting from N fertilization have adverse effects on the environment. Therefore, the goal of Indian agriculture has to be to “increase food-grain production with the minimum and efficient use of chemical fertilizers”. This calls for a sincere effort on the part of agricultural scientists including extension workers to increase the efficiency of fertilizers applied in the farm fields. An effective nutrient management involves development of site specific nutrient recommendations including balanced NPK doses, timely application of fertilizers using appropriate methods, development and production of slow-release N fertilizers and indigenous nitrification inhibitors, and developing and practicing an integrated plant nutrient supply system (IPNS) using chemical fertilizers, organic manures, crop residues, and biofertilizers. In addition to proper nutrient management, other aspects of soil and crop management including the use of high yielding, nutrient-efficient cultivars, correcting soil physical and chemical problems and water management, disease and pest management (IPM), and post-harvest care and safe storage are important to achieve high fertilizer use efficiency.

Effect of vermicompost enriched with rock phosphate on the yield and uptake of nutrients in cowpea ( Vigna unguiculata [L. ] Walp)

Abstract: A field experiment was conducted in a Rhodic Haplustox during 1997-98 to study the effect of enriched vermicompost on the yield and uptake of nutrients by cowpea. Among the different treatments tried, enriched vermicompost showed its superiority over other treatments for yield and uptake of major nutrients like N, P, K, Ca and Mg. But the micronutrient uptake was not significantly influenced by any of the treatment.

Usefulness of Trichoderma and Pseudomonas against Rhizoctonia solani and Fusarium oxysporum infecting tomato

Abstract: The general inadequacy of chemical fungicides to tackle Rhizoctonia solani and Fusarium oxysporum diseases in tomato has led to the search for biocontrol solutions to these maladies. Twenty-six local isolates of Trichoderma spp. and 56 isolates of fluorescent pseudomonads from Kerala were evaluated for their antagonistic activity against R. solani and F. oxysporum under in vitro conditions. Different isolates showed varying degrees of antagonism. The two most antagonistic isolates against R. solani were T. pseudokoningii TR17 and T. harzianum TR20. Likewise, T. viride TR19 and TR22 formed the most effective isolates against F. oxysporum. Production of volatile and non-volatile antibiotic compounds varied among these isolates. Of the fluorescent pseudomonads, Pseudomonas fluorescens isolates P28 and P51 showed the greatest inhibition against R. solani whereas against F. oxysporum , P20 and P28 were most effective. Isolates obtained from the phylloplane were generally unsuccessful. Inhibitory property of the antagonistic bacteria was also media-dependent. Many of the pseudomonads, which inhibited the pathogens on KMB agar, failed to retard the pathogen’s growth on the PDA medium. The bacterial and fungal antagonists were also not mutually antagonistic as their co-inoculation hardly inhibited each other.

Land use in Kerala: changing scenarios and shifting paradigms

Abstract: Agricultural land-use changes in Kerala during the past half-century were marked by an initial increase in total cropped area (26% between 1960 and 1969), followed by dramatic shifts in the coverage of individual crops. For example, rice area dropped by 60% between 1975 and 2003, while the cultivation of coconut, rubber, arecanut and banana+plantains increased spectacularly (106, 627, 41 and 96% respectively between 1955 and 2000). Agricultural expansion coupled with over-exploitation of forests has affected the state's forest ecosystems, however. Primary forests dropped substantially between 1940 and 1970—average loss of publicly managed forests being 5000 ha per year. Satellite imageries show a further drop thereafter, with a concomitant loss of biodiversity. As monospecific cultivation methods became extensive and the live fences/scattered trees on farmlands were decimated, the capacity within the agricultural sector to meet its own demands (green manure, poles, fodder, firewood and timber) also reduced, which in turn, increased the dependence on forestlands. In the light of environmental degradation and the need for climate change mitigation, a paradigm shift in the state's land management is imperative. Agroforestry, which aims at optimizing productivity and above all, sustainability, has the potential to provide many resources for which the people have traditionally depended on forests. Yet, as a modern land management strategy, agroforestry has not received adequate attention in Kerala. Agroforests if established on degraded lands will not only reduce the anthropogenic pressure on existing forest resources but also will enhance the sink potential of CO 2 .