19982015
  • Authors:
    • Lal, R.
    • Blanco-Canqui, H.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 2
  • Year: 2009
  • Summary: Franzluebbers (2009) is right about the need for a more intensive soil sampling, "repeated sampling with time,"and "stratified sampling" as well as for the use of multiple fields and collection of larger number of pseudoreplicates to overcome the high field variability in soil organic carbon (SOC) pools within each Major Land Resource Area (MLRA). The selected fields were representative of each MLRA in terms of soil type, slope, and management, but it is correct that a single soil would not capture all the variability in soil and management for the whole MLRA. This study was not intended to relate the data from the single soil to the whole MLRA but rather to emphasize the differences in SOC sequestration rates among the three management systems within each soil.
  • Authors:
    • Cadisch, G.
    • Giller, K.
    • Kamiri, H.
    • Gathumbi, S.
    • Ndufa, J.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 6
  • Year: 2009
  • Summary: The deliberate planting of fast-growing N 2-fixing legume monoculture species in rotation with cereal crops can be an important source of N for soil fertility replenishment. We hypothesized that mixed-species fallows have a higher potential of giving long-term residual benefits in terms of biomass, nutrients, and quality of residuals leading to long-term nutrient supply to postfallow maize ( Zea mays L.) crops. To test these hypotheses, two experiments were established in farmers' fields on very fine Kandiudalfic Eutrudox soils with monoculture and mixed-species fallows. Treatments included: sesbania [ Sesbania sesban (L.) Merr.], crotalaria ( Crotalaria grahamiana Wight and Arn.), pigeonpea [ Cajanus cajan (L.) Millsp.], siratro [ Macroptilium atropurpureum (DC.) Urb.], and calliandra ( Calliandra calothyrsus Meissn.) as monoculture-species fallow and mixture fallows of sesbania+crotalaria, sesbania+pigeonpea, sesbania+siratro, or sesbania+calliandra compared with continuous maize cropping with or without N fertilizer, and natural weed fallow. Total aboveground biomass ranged from 4.1 to 20.5 Mg ha -1 for monoculture and 7.8 to 23.3 Mg ha -1 for mixed-species fallows. Recyclable fallow biomass N ranged from 70 to 313 kg ha -1 and there was a positive interaction in some mixtures leading to increased N accumulation. Postfallow maize yields for fallows over five cropping seasons were 161-272% or 61-103% higher when compared with continuous maize without or with N fertilizer, respectively. Long-term postfallow effects on maize yield were linearly related to the amount of recycled fallow N yield. Thus, choice of fallow species to mix should be primarily driven by a better risk management strategy and an increased basket of multiple products and services.
  • Authors:
    • Oliveira, E.
    • Baliza, D.
    • Rodrigues, T.
    • Avila, F.
    • Faquin, V.
    • Rodrigues, C.
  • Source: CIENCIA E AGROTECNOLOGIA
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: This study investigated the effect of the previous cultivation of different forage grasses fertilized with triple superphosphate (TSP) and reactive Arad phosphate (RAP) on growth, yield, and accumulation of P by soyabean. Two experiments were carried out: one in Haplic Cambisol typical distrophic, medium texture and the other in Red Latosol typical distrophic very clayey texture. For both experiments, the experimental design was a completely randomized one in a 4*2*2 factorial scheme; the previous crop being of four forage grasses utilized as cover plants in no-tillage system ( Brachiaria decumbens [Urochloa decumbens], Brachiaria brizantha [U. brizantha], millet and forage sorghum) fertilized with two sources of P (RAP and TSP) and two additional treatments, which are the cultivation of soyabean and bean plant without the previous growing of cover plants, and also fertilized with TSP and RAP. The plants were harvested after they had completed the development cycle. Grain and shoot dry matter yield and P accumulation in the shoot and in the grains of soyabean were determined. The forage plants immobilized the P of TSP, reducing the residual effect for soyabean. When forage grasses are fertilized with RAP, there is increased residual effect with increasing yield of soyabean in succession to the cover plants, with exception for the growing in succession to B. brizantha.
  • Authors:
    • Monteiro, J. E. B. A.
  • Source: Agrometeorologia dos cultivos: o fator meteorológico na produção agrícola
  • Year: 2009
  • Summary: This book brings together a broad base of information on 32 major Brazilian agricultural crops and their relations with climate. The focus of the book is not on the methodologies and applications of agrometeorology per se, but rather restricts its focus to crops and traits that determine yield as a function of the environment. The crops included are rice, castor oil, sunflowers, pineapples, soyabeans, triticale, maize, potatoes, barley, peanuts, oats, onions, canola, wheat, cotton, beans, sugarcane, Pinus, black wattle ( Acacia mearnsii), tropical and temperate grapes, coconuts, citrus, bananas, sisal, cocoa, coffee, apples, Jatropha, Eucalyptus and the fodder plants Cynodon, Brachiaria and Panicum. The contents of the book are divided into three main parts, I. Introduction, II. Temporary crops and III. Permanent crops, with each chapter within parts II and III dedicated to a particular crop, and covering: (1) the main features of farming and phenology; (2) agrometeorological productivity constraints - water availability, temperature, solar radiation, photoperiod and wind; and (3) adverse events - hail and rainstorms, droughts and dry spells, winds and gales, frost, and too much rain and over-prolonged drought. The book was organized by the National Institute of Meteorology and had the collaboration of 105 researchers from 37 Brazilian institutions (federal and state), research centres, institutes and universities.
  • Authors:
    • Tom, C. T.
    • Ngwuta, A. A.
    • Ibeawuchi, I. I.
    • Ogoke, I. J.
    • Onweremadu, E. U.
  • Source: Journal of Sustainable Agriculture
  • Volume: 33
  • Issue: 8
  • Year: 2009
  • Summary: Soil nutrient and physical status in small holder farms in southeastern Nigeria are subjected to debilitating effects of continuous cropping without adequate efforts towards replenishment and conservation to ensure sustainability of soil resources. Although inorganic fertilizers are quick acting for soil nutrient enhancement, to guarantee soil health they must be used within the context of integrated soil fertility management relative to soil type and other climatic conditions. On the other hand, apart from maintaining required nutrient levels, the use of appropriate crop combinations and arrangements in farmers' fields can improve soil health. Leguminous plants including tree, shrub and annual species have been determined to be useful components in such systems. These species can contribute immensely to soil carbon and other mineral contents in addition to improving soil physical properties. Apart from their high edible protein content, some leguminous seeds also have high phytate content, which should enhance the bioavailability of Zn, making them good nutrient sources in human and animal nutrition. However, indigenous leguminous tree, shrub, and grain legume species are currently underutilized in the common cropping systems on smallholder farms. While tree species are lost through logging, with very limited research toward their improvement, research on grain legumes has been limited in this zone resulting in the loss of indigenous grain species. Low available soil P is another constraint to legume cultivation in this region that has to be addressed through well coordinated agronomic research. Increased and sustainable food production on small holder farms in southeastern Nigeria is possible with improved practices within the prevailing cropping systems. This is achievable with intensive breeding, agronomic and utilization studies on legume species in the cropping systems.
  • Authors:
    • Garcia-Oliva, F.
    • Prat, C.
    • Medina-Orozco, L.
    • Mendoza, M. E.
    • Bravo-Espinosa, M.
    • Lopez-Granados, E.
  • Source: Land Degradation & Development
  • Volume: 20
  • Issue: 6
  • Year: 2009
  • Summary: In the Transmexican Volcanic Belt a traditional fallow system is practiced, called "ano y vez" (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002-2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (
  • Authors:
    • Changade, N. M.
    • Khodke, U. M.
    • Chavan, M. L.
  • Source: International Journal of Agricultural Engineering
  • Volume: 2
  • Issue: 2
  • Year: 2009
  • Summary: Historical weather data can be used to develop and modify the management practices to increase the production with the conjunctive use of rain and irrigation water as per the water needs of the crop. Regional scale crop and water resource planning needs determination of reference crop evapotranspiration (eto), probability distribution of rainfall and ETo, and estimates of magnitude and duration of water deficit and surplus which can promote crop production in both irrigated and dryland areas. Daily weather data of 16 years (from 1984 to 2001) for five locations i.e., Aurangabad, Beed, Nanded, Parbhani and Osmanabad of Marathwada region was used to determine reference crop evapotranspiration (ETo). The rainfall and ETo data were analysed to ascertain their fit to various probability distributions. The goodness of fit was determined by chi 2 tests. The developed crop coefficients were used to estimate crop water requirements of 8 major crops of the region. Effective rainfall was used to determine the weeks at which the rainfall exceed or fall deficit of crop water requirement. The study indicated that normal distribution gave the closest fit to the weekly rainfall and ETo data. The seasonal water requirement of cotton, groundnut, sugarcane and banana is higher at Parbhani whereas that of kharif sorghum, rabi sorghum, wheat and soybean is higher at Osmanabad than other places in the region, the effective rainfall meets the water need of kharif sorghum and soybean. The rainfall values during the critical growth stages of rabi (sorghum and wheat) and summer crops (groundnut, banana and sugarcane) are deficit than their water requirement in the respective weeks and hence require irrigation during those periods. Among the row crops, wheat and groundnut can only be grown under irrigation. Annual excess rainfall for various crops ranges between 561-749 mm for kharif sorghum, 124-195 mm for rabi sorghum, 0-15 mm for wheat, 624-808 mm for soybean, 633-786 mm for cotton, 453-609 mm for sugarcane and 526-703 mm for banana. If the excess rains are effectively harvested, the irrigation potential could be raised in the region.
  • Authors:
    • Place, F.
    • Ajayi, O. C.
    • Akinnifesi, F. K.
    • Sileshi, G.
  • Source: Plant and Soil
  • Volume: 307
  • Issue: 1-2
  • Year: 2008
  • Summary: A number of studies have tested the effect of woody and herbaceous legumes on soil fertility and maize yields in sub-Saharan Africa. However, their effects on maize productivity are much debated because results have been variable. A meta-analysis was conducted with the aim of evaluating the evidence in support of yield benefits from woody and herbaceous green manure legumes. A total of 94 peer-reviewed publications from West, East and southern Africa qualified for inclusion in the analysis. Maize yield from herbaceous green manure legumes (54 publications), non-coppicing legumes (48 publications), coppicing woody legumes (10 publications), natural fallows (29 publications), and fully fertilized monoculture maize (52 publications) were compared. Mixed linear modelling using yield differences (D) and response ratios (RR) indicated that the response to legumes is positive. The mean yield increase (D) over unfertilized maize was highest (2.3 t ha-1) and least variable (CV=70%) in fully fertilized maize, while it was lowest (0.3 t ha-1) and most variable (CV=229%) in natural fallows. The increase in yield over unfertilized maize was 1.6 t ha-1 with coppicing woody legumes, 1.3 t ha-1 with non-coppicing woody legumes and 0.8 t ha-1 with herbaceous green manure legumes. Doubling and tripling of yields relative to the control (RR > 2) was recorded in coppicing species (67% of the cases), non-coppicing legumes (45% of the cases), herbaceous green manure legumes (16% of the cases) and natural fallows (19% of the cases). However, doubling or tripling of yields occurred only in low and medium potential sites. Amending post-fallow plots with 50% of the recommended fertilizer dose further increased yields by over 25% indicating that legume rotations may play an important role in reducing fertilizer requirements. Except with the natural fallow, the 95% confidence intervals of D and RR were higher than 1 and 0, respectively indicating significant and positive response to treatments. Therefore, it is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows.
  • Authors:
    • Koch, B.
    • Siwe, R. N.
  • Source: Environmental monitoring and assessment
  • Volume: 145
  • Issue: 1-3
  • Year: 2008
  • Summary: The continuous extraction of wood and the conversion of forest to small- and large-scale agricultural parcels is rapidly changing the land cover of the mount Cameroon region. The changes occur at varying spatial scales most often not more than 2ha for the small-scale subsistence farms and above 10ha for the extensive agricultural plantations of cocoa and palm. Given the importance of land use and land cover data in conservation planning, accurate and efficient techniques to provide up-to-date change information are required. A number of techniques for realising the detection of land cover dynamics using remotely sensed imagery have been formulated, tested and assessed with the results varying with respect to the change scenario under investigation, the information required and the imagery applied. In this study the Change Vector Analysis (CVA) technique was implemented on multitemporal multispectral Landsat data from the Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) sensors to monitor the dynamics of forest change in the mount Cameroon region. CVA was applied to multi-temporal data to compare the differences in the time-trajectory of the tasseled cap greenness and brightness for two successive time periods - 1987 and 2002. The tasseled cap was selected as biophysical indicator because it optimises the data viewing capabilities of vegetation, representing the basic types of land cover - vegetation, soil and water. Classes were created arbitrarily to predict the technique's potential in monitoring forest cover changes in the mount Cameroon region. The efficiency of the technique could not be fully assessed due to the inavailability of sufficient ground truth data. Assessment was based on the establishment of an error matrix of change versus no-change. The overall accuracy was 70%. The technique nevertheless demonstrated immense potentials in monitoring forest cover change dynamics especially when complemented with field studies.
  • Authors:
    • Hairiah, K.
    • Weise, S.
    • Sonwa, D.
    • Mbile, P.
    • Agus, F.
    • Edadinata, A.
    • Meadu, V.
    • Robiglio, V.
    • Budidarsono, S.
    • Hyman, G.
    • Gockowski, J.
    • White, D.
    • Murdiyarso, D.
    • Dewi, S.
    • Van Noordwijk, M.
    • Swallow, B.
  • Year: 2007