• Authors:
    • Zheng, M.
    • Wang, T.
    • Li, Z.
    • Cai, C.
    • Guo, Z.
  • Source: Agroforestry Systems
  • Volume: 76
  • Issue: 1
  • Year: 2009
  • Summary: Land management practices that simultaneously improve soil properties are crucial to high crop production and minimize detrimental impact on the environment. The effects of crop residues on crop performance, the fluxes of soil N 2O and CO 2 under wheat-maize (WM) and/or faba bean-maize (FM) rotations in Amorpha fruticosa (A) and Vetiveria zizanioides (V) intercropping systems on a loamy clay soil, in subtropical China, were examined. Crop performance, soil N 2O and CO 2 as well as some potential factors such as soil water content, soil carbon, soil nitrogen, microbial biomass and N mineralization were recorded during 2006 maize crop cultivation. Soil N 2O and CO 2 fluxes are determined using a closed-based chamber. Maize yield was greater after faba bean than after wheat may be due to differences in supply of N from residues. The presence of hedgerow significantly improved maize grain yields. N 2O emissions from soils with maize were considerably greater after faba bean (345 g N 2O-N ha -1) than after wheat (289 g N 2O-N ha -1). However, the cumulated N 2O emissions did not differ significantly between WM and FM. The difference in N 2O emissions between WM and FM was mostly due to the amounts of crop residues. Hedgerow alley cropping tended to emit more N 2O than WM and FM, in particular A. fruticosa intercropping systems. Over the entire 118 days of measurement, the N 2O fluxes represented 534 g N 2O-N ha -1 (AWM) and 512 g N 2O-N ha -1 (AFM) under A. fruticosa species, 403 g N 2O-N ha -1 (VWM) and 423 g N 2O-N ha -1 (VFM) under Vetiver grass. A significantly higher CO 2 emission was observed in AFM (5335 kg CO 2-C ha -1) from June to October, whereas no significant difference was observed among WM (3480 kg CO 2-C ha -1), FM (3302 kg CO 2-C ha -1), AWM (3877 kg CO 2-C ha -1), VWM (3124 kg CO 2-C ha -1) and VFM (3309 kg CO 2-C ha -1), indicating the importance of A. fruticosa along with faba bean residue on CO 2 fluxes. As a result, crop residues and land conversion from agricultural to agroforestry can, in turn, influence microbial biomass, N mineralization, soil C and N content, which can further alter the magnitude of crop growth, soil N 2O and CO 2 emissions in the present environmental conditions.
  • Authors:
    • Nagaki, M.
    • Ke, F.
  • Source: Agricultural Information Research
  • Volume: 18
  • Issue: 2
  • Year: 2009
  • Summary: In the arid areas of Northwest China, agriculture especially crop farming consumes most of water resource. Water-intensive and low value-added wheat is cultivated as a staple food of the local people in large scale. Because of the surface water scarcity, irrigation mainly depends on pumping the groundwater in these areas. Based on field surveys conducted in 2005 and 2006 both in the south and the north of Minqin County, Gansu province, this study is designed to study the role of groundwater irrigation on wheat production and how to improve the technical efficiencies (TEs) of wheat farmers by estimating a Stochastic Frontier Production Function (SFPF). The above information is valuable for how to save wheat water consumption and improving the food safety in the arid areas. The empirical results showed that expenditure on pumping groundwater played important role in wheat production. Meanwhile, the same expenditure played more effectively on wheat intercropping with maize in the south than that in the north. As a result, the farmers in the south are more likely to increase expenditures on pumping water than the farmers in the north. Therefore, the government should make new program to restrict wheat water consumption and to secure the farmers in both areas to use the groundwater fairly. Meanwhile, it is suggested that younger farmers can achieve a higher TE both in the south and the north. For the input-intensive intercropping in the south, a larger family, higher education of the farm managers, and coordination of their part-time jobs with agricultural production activities can also help to get higher TEs.
  • Authors:
    • Cabezas, W. A. R. L.
    • Lange, A.
    • Trivelin, P. C. O.
  • Source: Revista Brasileira de Milho e Sorgo
  • Volume: 8
  • Issue: 1
  • Year: 2009
  • Summary: Strategies aiming to increase straw production by crops should be implemented in the Cerrado region in order to consolidate no-tillage cultivation. The objective of the present work was to evaluate the effect of time and splitting of supplementary nitrogen application to maize (in addition to the N-fertilization at seeding) on straw production and several yield components of black oat, a spontaneous native species. Treatments consisted of applying 70 kg ha -1 nitrogen in addition to maize fertilization at seeding, at distinct times: at black-oat seeding; 8 days before corn seeding; in covering in plants in the phases of 4-5 leaves and 6-7 leaves. At seeding, 42 kg N.ha -1 were applied in all plots. The nitrogen fertilization applied at oat seeding did not cause increase in out-of-season straw productivity. An increase in maize straw production was observed with nitrogen supply in addition to fertilization at seeding as well as the application closer to seeding resulted in an increased straw production when compared to fertilization at oat seeding.
  • Authors:
    • Logsdon, G.
  • Source: Small-scale grain raising
  • Issue: Ed.2
  • Year: 2009
  • Summary: This book (12 chapters) discusses the basics of the organic farming and processing of whole grains (specifically maize, wheat, sorghum, oats, dry beans, rye and barley, buckwheat and millet, rice, some uncommon grains, and legumes) for home gardeners and small-scale farmers. Topics covered include planting; pest, weed and disease management; harvesting; and processing, storing and using whole grains. Some recipes are also included.
  • Authors:
    • Rosenthal, M. D.
    • Pinho, C. F.
    • Machado, A.
    • Noldin, J. A.
    • Pinto, J. J. O.
    • Donida, A.
    • Galon, L.
    • Durigan ,M.
  • Source: PLANTA DANINHA
  • Volume: 27
  • Issue: Especial
  • Year: 2009
  • Summary: The objective of this study was to evaluate the residual soil activity of herbicide (imazethapyr+imazapic), labeled for the Clearfield (CL) system and using corn, cv. Biomatrix 2202, as a bioindicator. The study was carried out in a greenhouse, at the Universidade Federal de Pelotas, in southern Brazil. Rice, cv. IRGA 422 CL, was planted in boxes (60*40*20 cm). At the 3-4 leaf stage, the herbicide Only (imazethapyr+imazapic) was sprayed at 0; 25+75; 37.5+112.5 and 50+150 g ha -1. After harvesting the rice, boxes were kept without flooding for 45 days. Black oat (Avena strigosa) was planted to keep the soil covered during the winter. In the spring, oat was harvested and 360 or 540 days after herbicide application (DAA), the soil from the boxes was transferred to two sets of pots labeled as experiment 1 (main corn crop) and experiment 2 (minor corn crop), respectively. The soil for experiment 2 was kept drained during the time period between seeding the two studies (360 to 540 DAA). Corn was planted in both studies and harvested at the 4-5 leaf stages. The variables evaluated were shoot and root biomass, plant height and leaf area index (for experiment 2). The data from both studies were analyzed using ANOVA (
  • Authors:
    • Davis, A.
    • Tracy, B.
  • Source: Crop Science
  • Volume: 49
  • Issue: 4
  • Year: 2009
  • Summary: Crop and livestock production are rarely integrated together in modern farming systems. Reintegrating crops with livestock production has been shown to produce many agronomic and environmental benefits. The objective of this study was to evaluate how an integrated crop-livestock system would influence weed biomass and weed species composition compared with a conventional, continuous corn ( Zea mays L.) cropping system. The experimental farming system used in this study was established on a 90-ha site near Pana, IL, in 2002. The integrated system included two phases: (i) a corn and oat ( Avena sativa L.) cash crop rotation, grown in summer, and (ii) post-harvest grazing of corn stover with annual cover crops. Over a 4-yr period (2004-2007), weed biomass was approximately 4.5 times higher in the conventional system (8.4 g m -2) compared with the integrated system (1.8 g m -2). Weed species composition was affected by the integrated system and showed a temporal disjunction between the time of year and weed life history. Surprisingly, cattle grazing on cropland had little effect on weed biomass or species composition. The primary drivers that suppress weed biomass and change species composition appear to be use of crop rotation and annual cover crops within the integrated system. Wider adoption of integrated crop-livestock systems, such as the one used in this study, should reduce reliance on herbicides compared with more conventional cropping systems.
  • Authors:
    • Ernani, P.
    • Zanatta, J.
    • Bayer, C.
    • Vieira, F.
  • Source: Australian Journal of Soil Research
  • Volume: 47
  • Issue: 7
  • Year: 2009
  • Summary: Nitrogen-fixing crops and N fertilisation increase soil acidification, but few studies have attempted to evaluate the capacity of soil organic matter to alleviate the Al toxicity in acid no-tilled soils. This study was carried out in a 21-year-old experiment aiming to evaluate the effect of crop systems [fallow/maize ( Zea mays L.), F/M; oat ( Avena strigosa Schreb)/maize, O/M; oat+vetch ( Vigna sativa L.)/maize, O+V/M; lablab ( Dolichos lablab)+maize, L+M; and pigeon pea ( Cajanus cajan L. Millsp.)+maize, P+M] and mineral N fertilisation (0 and 149 kg/ha.year) on chemical attributes and Al speciation in the 0-0.05 and 0.05-0.10 m layers of a no-tilled Paleudult of Southern Brazil. The original soil pH (5.8) decreased in all crop systems, declining 0.37-1.52 units in 21 years without re-liming. This decrease was larger in subsoil layers and, in general, was exacerbated by legume-based crop systems and by N fertilisation. The drop in soil pH increased Al content in solid phase (range 0.07-1.85 cmol c/kg) and in soil solution (range 0.01-0.06 mmol/L), and decreased base saturation on cation exchange capacity (range 12.5-61.2%). However, the Al 3+ activity in the soil solution (1.03*10 -7-9.3*10 -8) was kept below threshold values of toxicity to maize roots, primarily due to the formation of organometallic complexes at low pH, which was estimated as up to 90% of the total Al in solution, but also due to the increased ionic strength in this no-till soil (0.0026-0.0104). Our results highlight that, although legume cover crops and N fertilisation can accelerate soil acidification, Al toxicity is offset by increased organic matter in no-till subtropical soils.
  • Authors:
    • Teixeira, H.
    • Paula Junior, T.
    • Vieira, R.
    • Vieira, C.
  • Source: CIENCIA E AGROTECNOLOGIA
  • Volume: 33
  • Issue: special issue
  • Year: 2009
  • Summary: In order to evaluate the intensity of angular leaf spot ( Pseudocercospora griseola; ALS) and anthracnose ( Colletotrichum lindemuthianum; ANT) on pods, 9 genotypes of common bean were planted in 3 cropping systems in Brazil: monocrop (MC); monocrop grown on trellises (MCT); and intercrop with maize (ICM). In MC, beans were planted 0.5 m apart. Trelisses were set up with 1.8 m high bamboos and beans were sown 0.65 m apart. In ICM, beans were planted simultaneously with maize and in its rows. This cereal was sown 1.0 m apart with 4 plants/m. Each cropping system was an independent trial installed close to each other. Climbing genotypes of beans most susceptible to ALS had less diseased pods in ICM than in both MC and MCT, but the less susceptible genotypes, regardless of their growth type, as well as the susceptible bush and semi-climbing genotypes, were similarly attacked by ALS in the three systems. ANT on pods of the susceptible bean cv. Perola was less intense in MCT than in MC and less intense in ICM than in MCT. ANT seed transmission was 11, 9.1 and 4.4% when seeds came from MC, MCT and ICM, respectively.
  • Authors:
    • Sanginga, N.
    • Olufajo, O.
    • Iwuafor, E.
    • Abaidoo, R.
    • Yusuf, A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 129
  • Issue: 1/3
  • Year: 2009
  • Summary: Understanding changes in soil chemical and biological properties is important in explaining the mechanism involved in the yield increases of cereals following legumes in rotation. Field trials were conducted between 2003 and 2005 to compare the effect of six 2-year rotations involving two genotypes each of cowpea (IT 96D-724 and SAMPEA-7) and soybean (TGx 1448-2E and SAMSOY-2), a natural bush fallow and maize on soil microbial and chemical properties and yield of subsequent maize. Changes in soil pH, total nitrogen (N tot), organic carbon (C org), water soluble carbon (WSC), microbial biomass carbon (C mic) and nitrogen (N mic) were measured under different cropping systems. Cropping sequence has no significant ( P>0.05) effect on soil pH and C org, while WSC increased significantly when maize followed IT 96D-724 (100%), SAMPEA-7 (95%), TGx 1448-2E (79%) and SAMSOY-2 (106%) compared with continuous maize. On average, legume rotation caused 23% increase in N tot relative to continuous maize. The C mic and N mic values were significantly affected by cropping sequence. The highest values were found in legume-maize rotation and the lowest values were found in fallow-maize and continuous maize. On average, C mic made up to 4.8% of C org and N mic accounted for 4.4% of N tot under different cropping systems. Maize grain yield increased significantly following legumes and had strong positive correlation with C mic and N mic suggesting that they are associated with yield increases due to other rotation effects. Negative correlation of grain yield with C mic:N mic and C org:N tot indicate that high C:N ratios contribute to nitrogen immobilization in the soil and are detrimental to crop productivity. The results showed that integration of grain legumes will reverse this process and ensure maintenance of soil quality and maize crop yield, which on average, increased by 68% and 49% following soybean and cowpea, respectively compared to continuous maize.
  • Authors:
    • Zhu, C.
    • He, K.
    • Pan, M.
    • Mao, G.
    • Pan, G.
    • Zheng, Y.
  • Source: Guizhou Agricultural Sciences
  • Issue: 1
  • Year: 2009
  • Summary: This study investigated the effects of different intercropping and interplanting patterns of green manure on soil fertility in Guizhou, China. The results showed that maize yield in improved soil fertility areas under 1:1 application ratio between organic and inorganic fertilizer averagely increased by 23.05% (102.5 kg/667m 2) compared with the conventional application pattern. The yields of the potato-green manure-maize pattern, rape-green manure-maize pattern and wheat-green manure-maize pattern increased by 51.2-66.0 kg/667m 2, 146.1 kg/667 m 2 and 146.7 kg/667 m 2, respectively compared with the conventional application pattern. The soil organic matter, total nitrogen, alkaline hydrolysis nitrogen, active P and active K content in improved soil fertility areas averagely increased by 0.23%, 0.033%, 23.23 mg/kg, 1.5 mg/kg and 17.75 mg/kg respectively and the soil fertility was increased to varying degrees. The high maize yield depends on its strong and high plants and better economic characters.