High Land Use Research Articles

The profitability of maize–haricot bean intercropping techniques to control maize stem borers under low pest densities in Ethiopia

Lepidopteran stem borers are the main pests of cereals in Ethiopia. In recent years, habitat management techniques, which aim at increasing plant biodiversity through mixed cropping, have gained increased attention in stem borer control. In the present study, the profitability of mixed cropping of maize with haricot beans at different ratios and the effect on infestation of maize by stem borers, yield and borer parasitism were studied in Melkassa and Mieso, Ethiopia, in a field experiment under natural infestation. In Melkassa, pest infestations were too low for the cropping system to affect pests, plant damage and yields significantly, whereas in Mieso, where the pest densities were high, intercropping of maize with beans at ratios of 1:1 to 2:1 significantly decreased borer densities compared with pure maize stands. Chilo partellus (Swinhoe) and Cotesia flavipes. (Cameron) were the major stem borer and parasitoid species, respectively, recorded both at Melkassa and Mieso. Borer parasitism was higher at Mieso than at Melkassa and tended to increase with the increase of the haricot bean ratio in the intercropping system. Land equivalent ratios of >1 indicated higher land use efficiency in mixed compared with sole cropping, even if pest densities were low.

Agricultural Land Use and Biodiversity in the Alps

Alpine grasslands are ecosystems with a great diversity of plant species. However, little is known about other levels of biodiversity, such as landscape diversity, diversity of biological interactions of plants with herbivores or fungal pathogens, and genetic diversity. We therefore explored natural and anthropogenic determinants of grassland biodiversity at several levels of biological integration, from the genetic to the landscape level in the Swiss Alps. Differences between cultural traditions (Romanic, Germanic, and Walser) turned out to still affect land use diversity and thus landscape diversity. Increasing land use diversity, in turn, increased plant species diversity per village. However, recent land use changes have reduced this diversity. Within grassland parcels, plant species diversity was higher on unfertilized mown grasslands than on fertilized or grazed ones. Most individual plants were affected by herbivores and fungal leaf pathogens, reflecting that parcels harbored a great diversity of herbivores and pathogens. However, as plant damage by herbivores and pathogens was not severe, conserving these biological interactions among plants is hardly compromising agricultural goals. A common-garden experiment revealed genetic differentiation of the important fodder grass Poa alpina between mown and grazed sites, suggesting adaptation. Pervillage genetic diversity of Poa alpina was greater in villages with higher land use diversity, analogous to the higher plant species diversity there. Overall, landscape diversity and biodiversity within grassland parcels are currently declining. As this contradicts the intention of Swiss law and international agreements, financial incentives need to be re-allocated and should focus on promoting high biodiversity at the local and the landscape level. At the same time, this will benefit landscape attractiveness for tourists and help preserve a precious cultural heritage in the Swiss Alps.

Relationships between Danish organic farming and landscape composition

This article presents an investigation of relationships between organic farming and landscape composition in Denmark. Landscape composition was analysed in terms of density of uncultivated landscape elements (I), number of land uses per hectare (II), diversity of land use (III) and mean field size (IV). Two analytical approaches were used. The first was based on an examination of the national agricultural registers for 1998, 2001 and 2004. The second approach used aerial photo interpretation for an analysis of 72 conventional and 40 organic farms within three sample areas for 1982, 1995 and 2002. The national analysis indicated that organic farming has a direct effect on landscape composition. In 2001, organic farms were characterised by a higher number of land uses per ha, a higher land use diversity and smaller mean field sizes. From 1998 to 2004, conversion to organic farming was related to an increasing number of land uses per ha, increasing land-use diversity and decreasing mean field sizes. Relationships between organic farming and landscape composition were independent of variations in regional location, farm size or farm size change. At the level of sample areas, a significant relationship between organic farming and landscape composition was only found for densities of small biotopes. However, when differences in farm size and physical geographical conditions between conventional and organic farms were taken into account, several significant differences in landscape composition were clarified in two of the three sample areas. Furthermore, changes in landscape composition following conversion to organic farming were largely biased by the characteristics of the sample areas. Thus, in contrast to the national level, the sample area study indicated that differences in landscape composition between organic and conventional farms were not a direct implication of organic farming practices, but were related to variations within other parameters and to the location of organically farmed land.

Effect of plant populations on the productivity of plantain and cassava intercropping

Two plantain-cassava intercropping experiments were conducted at the Teaching and Research Farm of Obafemi Awolowo University, Ile–Ife. Each experiment was planted in a 2 x 2 factorial involving four mixture proportions arranged in Randomized Complete Block design with four replications. Growth, crop yields and productivity of plantain (Musa paradisiacal) and cassava (Manihot esculenta) were observed. The two intercrop populations for plantain were planted at 3 x 3m and 3 x 2m spacing. The two populations for cassava were planted at 1 x 1 and 1 x 0.5m spacing. In Experiment I, cassava was intercropped with plantain stands at the same time while in Experiment II, cassava was intercropped two months after plantain was planted. The results in Experiment I showed that growth, harvestable yields and productivity of plantain and cassava intercrops were enhanced by the plant populations of each intercrop Thus, suggesting that complementary rather than competitive yielding prevailed in the mixtures. The spatial and temporal factors in complementary yielding were discussed. The highest land use and monetary efficiency values were land equivalent ratio (LER), of 1.65, land equivalent coefficient (LEC) of 0.68 and monetary equivalent ratio (MER) of 1.62, which were obtained at the highest mixture plant population. Planting cassava two months after the planting of plantain (Experiment II) resulted in loss of intercropping advantage because plantain drastically affected associated cassava growth, yield and mixture productivity. Keywords: cassava, plantain, productivity, plant population Moor Journal of Agricultural Research Vol. 5(1) 2004: 26-32

Groundnut/Maize/Cassava Intercrop Yield Response to Fallow Age, Cropping Frequency and Crop Plant Density on an Ultisol in Southern Cameroon

ABSTRACT Two methods of intensifying crop production in ‘no-external-input’ slash and bum crop fallow rotation systems: increased crop density and increased cropping frequency, were tested on an Ultisol in southern Cameroon. Two common fallow types, secondary forest (forest fallow) and young volunteer regrowth dominated by Chromolaena odorata (bush fallow) were cleared, burned and planted to a groundnut/maize/cassava/plantain intercrop for one year or two consecutive years. Maize, cassava and plantain were planted at the ‘traditional’ low density, at a 30% higher density and at high density with Calliandra calothyrsus hedgerows as a soil fertility replenishment treatment. An increased maize density did not increase maize grain yield but reduced the groundnut grain yield in both years. Cassava root yield was not affected by planting density. In the second year of cropping, cassava yields were higher in bush fallow than in forest fallow. The cumulative maize grain yield of two consecutive years was unaffected by plant density in the bush fallow but was higher in the high plant density with C. calothyrsus than in low plant density in the forest fallow. Cumulative groundnut grain yields were higher in the low plant density than in high density in bush fallow and higher in the low density than the high density and the C. calothyrsus system in forest fallow. Cumulative cassava root yields had the same response as groundnut grain yields in the forest fallow, yet in the bush fallow, high and low plant density out-yielded the C. calothyrsus system. Yield increases through increased maize and cassava density were not possible. An increased total production through higher land use frequency appears possible at low plant density, yet not for maize. Alternative intensification options are discussed.

Effect of Crop Diversification of Rice-Wheat Cropping System on Productivity and Profitability

ABSTRACT Rice-wheat cropping system, being considered back bone of food self-sufficiency in many Asian countries, is facing sustainability problem and a need of crop diversification of this system is felt in recent years. A field study conducted for two years (1995-96 and 1996-97) at the Indian Agricultural Research Institute, New Delhi on a sandy clay loam soil indicated that partial diversification by inclusion of mungbean during summer (May-June) in rice-wheat system resulted in an increase in productivity and profitability. However, highest productivity was achieved when wheat was replaced by potato (followed by mungbean in summer) and highest profitability was achieved when wheat was replaced by clover. Rice-potato-mungbean cropping system increased productivity over rice-wheat system by 5.1 tha−1yr−1 and profitability by US $ 429 ha−1yr−1. Similarly, rice-clover cropping system gave 3.3 t ha−1yr−1 higher productivity and US $ 499 ha−1yr−1 higher profit than rice-wheat cropping system. Rice-rapeseed-mungbean also increased productivity over rice-wheat system by 1.8 t ha−1yr−1 and profitability by US $ 283 ha−1yr−1. Rice-wheat-mungbean cropping system recorded the maximum harvest density index, multiple cropping index and simultaneous cropping index, indicating higher land use efficiency than other rice based cropping systems. In view of higher productivity and more profit obtained with rice-potato-mungbean, rice-clover, rice-rapeseed-mungbean and rice-wheat-mungbean cropping systems as compared to rice-wheat cropping system, diversification of rice-wheat cropping system is recommended for sustainable production.

Childrens?? Physical Activity Places

Growing empirical evidence documents built environment effects on adults' physical activity, but little is known about environment effects on children's physical activity. Indeed, environments in which adults are active may differ significantly from the environments in which children are active, necessitating a sophisticated approach to public health and environment approaches to increase physical activity across the lifespan. Purpose To examine the relations between the number of places children are active and their levels of physical activity, neighborhood environment, and individual characteristics. Methods Parents of 201 children 4–18 years old were recruited from high and low walkable neighborhoods in King County, WA. Parents reported on the places where their children are active and the places' convenience to their home, their children's activity level, and individual characteristics. Results From a list of 15 potential places in which children could be active in a typical month, friends' homes, own yards, parks, and playgrounds were more frequently visited by children in order to be active than the street and gyms or other paid facilities. The number of places children went to be active was positively related to the number of activity-related facilities convenient to home (<10 minute walk from home) (p<.019), but the number of different children's activity places decreased with child age (p<.007). The number of places a child went to be active was positively related to their level of physical activity (p<.001). In contrast, children went to fewer places to be active when living in neighborhoods marked by environmental factors associated with higher adult physical activity, particularly adults walking for transport (e.g., higher residential density, higher land use mix) (p<.04). Conclusions Children's physical activity appears to benefit from a greater variety of places in which to be active and greater convenience of such activity places. However, the built environment in which adults are more active in the form of walking for transport may not necessarily translate into increased variety in the places in which children are active. Further evaluation of physical activity environments and the potential unique impact of such environments on children is warranted. Supported by NIH grant HL67350.

Yield stability of cassava, maize, soya bean and cowpea intercrops

The yield stability of intercropping systems is important in developing cropping systems that produce economic yields over a wide range of environments. Field studies were conducted during the 1997/98 and 1998/99 growing seasons at three locations in the forest and forest–savannah transition zones of Ghana to determine yield, land use efficiency and yield stability of cassava (Manihot esculenta), maize (Zea mays), soya bean (Glycine max) and cowpea (Vigna unguiculata) intercrop systems. The cropping systems consisted of a factorial combination of two cassava varieties: ‘Gblemoduade’ (an improved, highly branched variety) and ‘Ankra’ (a local variety with fewer branches) and three spatial arrangements. Cowpea rows were planted in the minor season into cassava as a successive crop to maize and soya bean after their harvest in the major season. Intercropping significantly reduced grain or tuber yield of maize, cassava ‘Gblemoduade’ and cassava ‘Ankra’ by 23–70%, 16–49% and 24–64%, respectively. Maize yield decreased with increased number of soya bean rows. ‘Gblemoduade’ outyielded ‘Ankra’ by more than 100% under both intercrop and sole crop. The yield of soya bean increased with increased number of soya bean rows, but did not differ in response to the cassava variety. However, cowpea yield was higher when intercropped with ‘Ankra’ than with ‘Gblemoduade’. The intercrops had higher land use ratios (LER=1·27–2·83) and were more stable than the sole crops. Intercrops involving ‘Ankra’ had higher LER (2·14–2·18) than systems with ‘Gblemoduade’ (LER=1·83–1·99), but their yield stabilities were similar.

Growth, Yield and Land Use Efficiency of Corn and Legumes Grown under Intercropping Systems

A field experiment was conducted at the experimental farm of Khon Kaen University in 2001. The objectives of this study were to investigate growth, yield and yield components of corn, peanut, soybean and mungbean under intercropping and single cropping, as well as to assess the land use efficiency. Yield and yield components of corn was unaffected by intercropping system. In legume crops; peanut, soybean and mungbean, intercropping systems reduced the leaf area and top dry weight per plant as compared with single cropping. Grain yield of peanut, soybean and mungbean was reduced by 28%, 39% and 51%, respectively, as compared with single cropping. The pod number per plant was the most affected by intercropping among the yield components. However, corn-legume intercropping increased land use efficiency by 48% to 66% depending on legume species. Corn-peanut intercropping gave the highest land use efficiency. The effects of light penetration and nutrient competition are discussed.

Efficiency of rice (Oryza sativa)-based crop sequences under coastal ecosystem

A field experiment conducted during 1994-95 and 1995-96 at Bhubaneswar revealed that preceding in situ green manuring of cowpea was beneficial for significant and highest grain yield of Cce (3.26 tlha). The yield aqributes such as panicle length, fertile grainslpanicleand harvest index were closely associated with the highest grain yield of rice. Rice-tomato (BT 10) recorded highest net return (Rs 60, 61 8.95lha) and benefit : cost ratio (4.42). Rice-groundnut recorded highest land use efficiency (63.86%) and energy output : input ratio (4.54). The production efficiency was however, superior (105.61 kglhalday) in rice-cabbage sequence.

Productivity, profitability and sustainability of Indian mustard (Brassica juncea) raised after different rainy season crops

A field investigation was carried out during 1994 96 at Kanpur, to judge the productivity, profitability and sustainability of lndian mustard [Brassica juncea (L.) Czernj. Cosson] raised after different rainy season crops. , lndian mustard yield maximized in green manured plot with Sesbania (32.73 qlha). The seed yield of lndian mus tard decreased (25.86 qlha) under fodder pearl millet [Pennisettim glaucum (L.) R.Br. emend. Stuntzl Indian mus tard sequential cropping. Computation of economics revealed that maize (Zea mays L.) Indian mustard sequential cropping recorded the highest lndian mustard seed equivalent (42.79 qlha), more net return (Rs 22.57 thousand1 ha) with highest land use efficiency (61.92%). Blackgram (Phaseolus mungo L.) Indian mustard remained next in order.

Social Implications of Land Use and Mode Choice

Three sets of analysis are described which suggest that the choice of public transportation is related to higher land use density. The first analysis is based on the New York Region's journey-to-work data of the 1960 census, concluding that higher employment and residential density will increase the proportion of transit users and that the proximity of jobs and housing to one another has important advantages for the low income worker because of shorter trip length. The second analysis, a theoretical examination of a hypothetical suburban area based on models developed in the first analysis, suggests that the clustering of housing around a large job concentration has benefits with regard to limiting highway construction. The third analysis suggests the residential densities at which public transportation can work. The trend today is away from the high densities that can support public transportation. The dilemma can be solved if higher densities of development are built.