The demand for food in Bangladesh is increasing due to the increasing population. Land is the primary natural resource that affords habitat and sustenance for living beings. In Bangladesh, the ...coastal areas cover an area of 47,201 km2 or 32 % of the total land under 19 districts of Bangladesh. The coastal southern saline and non-saline areas are vulnerable to water logging conditions and farmers cannot grow any crops except dry season (rabi). However, in some areas, farmers are trying to use their indigenous technologies to combat natural disasters to ensure food security. For example, floating, sorjan or raised bed systems are potential and farmers are practicing in these areas. Among these techniques, the sorjan bed system is one of the potential techniques that is extensively used in southern Bangladesh, particularly water logging conditions to improve food security. To enhance the production and make land cultivation profitable, the experiments were carried out at the farmers’ fields under the sorjan system in consecutive two growing seasons. The sole crop was brinjal (cv. BARI Begun-12), BARI Lalshak-1 (cv. Red amaranth), BARI Dhania-1 (cv. Coriander leaf), Cauliflower (cv. Cold queen), Cabbage (cv. Equatoria) and Knol Khol were utilized as intercropping with brinjal. The treatments were i) Sole brinjal, ii) Brinjal + Red amaranth, iii) Brinjal + Coriander leaf, iv) Brinjal + Cauliflower, v) Brinjal + Cabbage, and vi) Brinjal +. 24-day-old seedlings of the BARI Begun-12 grown in a nursery bed were transferred to the plots where the seeds of Red amaranth and Coriander leaf were directly sown. However, the seedlings of Cauliflower, Cabbage, and Knol Khol were also transplanted to the field after one week of transplanting brinjal. The results exposed that sole crops had the highest results in terms of days to flowering, days to first fruit set, days to first harvesting, leaf area, fruit length, fruit breadth, single fruit weight, fruits plant−1, fruit yield, TSS %, and dry matter %. In both years, brinjal exhibited the highest yield as the sole crop compared to intercropping. 48.12 t/ha and 46.27 t/ha in the first and second cropping seasons, respectively. In the first cropping season, Red amaranth, Coriander leaf, Cauliflower, Cabbage, and Knol Khol performed with a yield of 10.12, 7.23, 23.14, 22.87, and 9.05 t/ha. During the second cropping season, the same crops exhibited a yield of 10.05, 7.01, 23.09, 22.68, and 9.98 t/ha. The highest land equivalent ratio, gross return, net return, and BCR were obtained from brinjal-cauliflower intercropping, which was 1.74, 1049300 BDT, 553820 BDT, and 2.12, respectively, in the 2021–2022 cropping season and 1.78, 1057900 BDT, 562010 BDT, and 2.13, respectively, in the next season in 2022–2023. This intercropping approach resulted in a higher land equivalent ratio, net return, and benefit-cost ratio of 1.76, 557915 BDT, and 2.125, respectively, over the average of two successive cropping seasons.
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•The demand for food in Bangladesh is increasing due to the increasing population.•Land is the primary natural resource that affords habitat and sustenance for living beings.•The coastal southern saline and non-saline regions are vulnerable to water logging conditions.•Although in these areas, farmers use indigenous non-profitable technologies to combat natural disasters to ensure food security.•The sorjan farming system has been found a potential, profitable and environmentally friendly farming practice in these vulnerable areas.
Intercropping is a farming practice involving two or more crop species, or genotypes, growing together and coexisting for a time. On the fringes of modern intensive agriculture, intercropping is ...important in many subsistence or low‐input/resource‐limited agricultural systems. By allowing genuine yield gains without increased inputs, or greater stability of yield with decreased inputs, intercropping could be one route to delivering ‘sustainable intensification’. We discuss how recent knowledge from agronomy, plant physiology and ecology can be combined with the aim of improving intercropping systems. Recent advances in agronomy and plant physiology include better understanding of the mechanisms of interactions between crop genotypes and species – for example, enhanced resource availability through niche complementarity. Ecological advances include better understanding of the context‐dependency of interactions, the mechanisms behind disease and pest avoidance, the links between above‐ and below‐ground systems, and the role of microtopographic variation in coexistence. This improved understanding can guide approaches for improving intercropping systems, including breeding crops for intercropping. Although such advances can help to improve intercropping systems, we suggest that other topics also need addressing. These include better assessment of the wider benefits of intercropping in terms of multiple ecosystem services, collaboration with agricultural engineering, and more effective interdisciplinary research.
Aims
Intercropping cereals with legumes may achieve high crop yields at reduced input levels. Several studies have indicated that intercropping increases phosphorus use efficiency but no overarching ...analysis exists on the role of species traits and input levels. Here we synthesize the available information on P use efficiency in cereal/legume intercropping.
Methods
Global data on yields, P uptake and nutrient input in cereal/legume mixtures were extracted from the literature and statistically analyzed. Co-variables explaining P uptake efficiency and yield were considered.
Results
P uptake was substantially increased with an average value of LER
P
, the land equivalent ratio for P uptake, of 1.24, and an average NE
P
(observed P uptake minus expected P uptake) of 3.67 kg P ha
−1
. The conversion efficiency of P uptake to biomass decreased with P uptake and was lower in intercrops than in sole crops but the conversion efficiency to yield was not affected by intercropping. The P fertilizer requirement was 21% lower in intercrops than in sole crops for the same yields.
Conclusions
Substantial improvements in land use efficiency and P uptake are obtained by cereal/legume intercropping. Cereal/legume intercropping has therefore potential to increase P fertilizer use efficiency in agriculture.
•Interspecific water competition existed between rubber trees and intercrops.•Observed water uptake complementarity differed from that of previous reports.•Intercrops could promote surface soil water ...availability for rubber trees.•Facilitative effects were most marked in rubber-galangal agroforestry.
Despite the development of rubber agroforestry systems for ecological and economic benefits in Southeast Asia, knowledge of their water uptake dynamics and interspecific water interactions remains limited. The objective of this study is to reveal the water relations (i.e., competition/complementarity) between rubber (Hevea brasiliensis) trees and different kinds of intercrops. We investigated the stable isotopes (δD and δ18O), fine root length density, and soil water content (SWC) under three agroforestry practices and one rubber monoculture across a year (2017/2018). Our results indicated that rubber trees acquired more than 40.5 ± 21.3 % of their water from shallow (0−20 cm) soil stratum, as do perennial galangal (Alpinia officinarum), tea (Camellia sinensis), and cocoa (Theobroma cacao). The complementarity hypothesis was not supported for rubber trees and the intercrops. In the dry season (November to April), there was strong interspecific competition for shallow water resources where the intercropping was practiced. However, intercropping increased the available soil water, enabling rubber trees to acquire more (9.4–24.3 %) shallow soil water. In the wet season (May to October), interspecific water competition was less pronounced based on the relative difference in soil water content (RDSW). Higher relative water content, in the order rubber-galangal > rubber-tea > rubber-cocoa, further showed that facilitative effects dominated interspecific water competition in all the agroforestry practices. This information regarding water relations between rubber trees and their intercrops will be essential to optimize land and water resource utilization in this region.
Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We ...discuss examples of facilitative root interactions in intercropped agroecosystems; including nitrogen transfer between legumes and non-leguminous plants, exploitation of the soil via mycorrhizal fungi and soil-plant processes which alter the mobilisation of plant growth resources such as through exudation of amino acids, extra-cellular enzymes, acidification, competition-induced modification of root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more intensified cropping systems using chemical and mechanical inputs also show that facilitative interactions definitely can be of significance. It is concluded that a better understanding of the mechanisms behind facilitative interactions may allow us to benefit more from these phenomena in agriculture and environmental management.
Intercropping ensures multiple benefits like enhancement of yield, environmental security, production sustainability, and greater ecosystem services. In order to better understand how mixed crop ...cultures mitigate stressful conditions, this study aims to highlight the beneficial effect of the intercropping legume-cereal in enhancing nutrient uptake for plant growth and productivity in low phosphorus (P) soils. To address this question, faba bean (Vicia faba L. cv. Sidi Aich) and barley (Hordeum vulgare L. cv. Rihane 3) were grown as sole- and inter-crops over two growing seasons in 2017 and 2018 in a northern Algerian agro-ecosystem with a semiarid Mediterranean climate. The results showed that the plant growth and nodulation were significantly increased by 18% and 32%, respectively, for intercropping than for sole cropping and so more in 2018 compared to 2017. Moreover, grain yield and resource use efficiency (N and P) were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. Also, the P and N concentrations measured in the rhizosphere were increased compared to bulk soil and even more so in the rhizosphere of intercropped species over two seasons. Our findings suggest that intercropping cereals with legumes may achieve high crop productivity and land use efficiency at reduced input levels.
Biodiversity can support a greener revolution in Africa Snapp, Sieglinde S.; Blackie, Malcolm J.; Gilbert, Robert A. ...
Proceedings of the National Academy of Sciences - PNAS,
11/2010, Letnik:
107, Številka:
48
Journal Article
Recenzirano
Odprti dostop
The Asian green revolution trebled grain yields through agro-chemical intensification of monocultures. Associated environmental costs have subsequently emerged. A rapidly changing world necessitates ...sustainability principles be developed to reinvent these technologies and test them at scale. The need is particularly urgent in Africa, where ecosystems are degrading and crop yields have stagnated. An unprecedented opportunity to reverse this trend is unfolding in Malawi, where a 90% subsidy has ensured access to fertilization and improved maize seed, with substantive gains in productivity for millions of farmers. To test if economic and ecological sustainability could be improved, we preformed manipulative experimentation with crop diversity in a countrywide trial (n = 991) and at adaptive, local scales through a decade of participatory research (n = 146). Spatial and temporal treatments compared monoculture maize with legume-diversified maize that included annual and semiperennial (SP) growth habits in temporal and spatial combinations, including rotation, SP rotation, intercrop, and SP intercrop systems. Modest fertilizer intensification doubled grain yield compared with monoculture maize. Biodiversity improved ecosystem function further: SP rotation systems at half-fertilizer rates produced equivalent quantities of grain, on a more stable basis (yield variability reduced from 22% to 13%) compared with monoculture. Across sites, profitability and farmer preference matched: SP rotations provided twofold superior returns, whereas diversification of maize with annual legumes provided more modest returns. In this study, we provide evidence that in Africa, crop diversification can be effective at a countrywide scale, and that shrubby, grain legumes can enhance environmental and food security.
Abstract Understanding the composition and dynamics of ecological communities is challenging because of the large number of organisms present and their numerous interactions. Among agricultural ...systems, intercropping considerably increases the complexity of communities compared to monocultures and alternative host plants can influence insect pest damage. Using literature records, we construct and analyse connectance trophic webs of date palm ( Phoenix dactylifera ) agro-ecosystems, including and excluding intercrops. Estimates of connectance (community complexity) are relatively low and little affected by consideration of intercrops. Plant–herbivore overlap is relatively high, suggesting that herbivores are typically not specialists. Herbivore–natural enemy overlap is greater when intercrops are considered, suggesting that diffuse apparent competition regulates pest populations. We pay particular attention to how trophic web structure might affect Batrachedra amydraula (Lesser date moth), an important economic pest. Records indicate it having 15 species of natural enemies and sharing 9 of these with other herbivores; these may maintain populations of natural enemies when the moth is seasonally rare, contributing to pest suppression. The estimated potential for apparent competition between the lesser date moth and other herbivores is higher when intercrops are considered. The consequent expectation of less severe infestations in plantations that are intercropped compared to monocultures matches empirically derived reports. Further, comparing results obtained from the literature on one country (Oman) and from 15 Middle Eastern countries, we find that community metric estimates are relatively little affected by the geographical scale considered. Overall, our results suggest that literature-based trophic web construction can provide an efficient and robust alternative, or in addition, to direct empirical methodologies and that the presence of intercrops will contribute to major pest suppression via indirect apparent competition.
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