• Authors:
    • N'Dayegamiye,A.
    • Whalen,J. K.
    • Tremblay,G.
    • Nyiraneza,J.
    • Grenier,M.
    • Drapeau,A.
    • Bipfubusa,M.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Legume crops leave N-rich residues and improve soil properties that can boost the yield of subsequent crops. This study conducted at two sites in Quebec, eastern Canada, identified the most appropriate preceding legume crops for subsequent corn ( Zea mays L.) and wheat ( Triticum aestivum L.) yield and N nutrition. Legumes were established in 2011, in monoculture or mixed with grain crops, for a total of 13 treatments: common bean ( Phaseolus vulgaris L.), soybean ( Glycine max L.), dry pea ( Pisum sativum L.), hairy vetch ( Vicia villosa Roth), alfalfa ( Medicago sativa L.), and crimson clover ( Trifolium incarnatum L.), (hairy vetch/wheat, crimson clover/wheat, field pea/wheat, alfalfa/corn, hairy vetch/corn, crimson clover/corn) and a non-N fixing crop (corn) as the control. In 2012, each plot was split and five N fertilizer rates applied to corn and wheat. Four legume systems (alfalfa, hairy vetch, crimson clover, and hairy vetch/wheat) significantly increased the soil structure stability, alkaline phosphatase and dehydrogenase activities at warmer St-Mathieu-de-Beloeil location but not at the cooler St-Lambert-de-Lauzon site. These legumes also significantly increased yields and N nutrition of corn and wheat at St Mathieu-de-Beloeil and of wheat only at St-Lambert-de-Lauzon. Although legume N credit was found low (~30 kg N ha -1), the N fertilizer replacement value was 51 to 77 kg N ha -1 for corn and up to 37 kg N ha -1 for wheat, depending on the preceding legume crop. This suggests that indirect effects related to improved soil properties impacted positively corn and wheat yield and N nutrition.
  • Authors:
    • Salazar,Osvaldo
    • Rojas,Claudia
    • Avendano,Fernando
    • Realini,Piero
    • Najera,Francisco
    • Tapia,Yasna
  • Source: Web Of Knowledge
  • Volume: 102
  • Issue: 3
  • Year: 2015
  • Summary: Vegetated buffer strips (BS) can help prevent nitrogen (N) losses from fields by subsurface lateral flow, thus protecting water resources. The purpose of this study was to determine if narrow BS would effectively remove dissolved inorganic N from subsurface lateral flow. Nitrate-N (NO3-N) and ammonia-N (NH3-N) concentrations in subsurface lateral flow were measured at 1 m depth in a BS system consisting of five treatments: G: strip of grass (Fescue arundinacea); GS: strip of grass and line of native shrubs (Fuchsia magellanica); GST1: strip of grass, line of shrubs and line of native trees 1 (Luma chequen); GST2: strip of grass, line of shrubs and line of native trees 2 (Drimys winteri); and C: bare soil as control. Water samples for the NO3-N and NH3-N measurements were collected between June 2012 and August 2014 in observation wells located at the inlet (input) and outlet (output) of each treatment. The analyses showed that vegetated BS had NO3-N removal efficiency ranging from 33 to 67 % (mean 52 %), with the G treatment showing the best performance in reducing NO3-N concentrations in subsurface lateral flow. The BS treatments were not effective in reducing NH3-N concentrations. The results suggested that N uptake by grass is the main process associated with the NO3-N retention capacity of vegetated BS.
  • Authors:
    • Schlegel,A. J.
    • Assefa,Y.
    • Bond,H. D.
    • Wetter,S. M.
    • Stone,L. R.
  • Source: Web Of Knowledge
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Cattle ( Bos taurus) manure and swine ( Sus scrofa) effluent are applied to cropland to recycle nutrients, build soil quality, and increase crop productivity. The objective of this study was to determine the long-term effects of land application of cattle manure and swine effluent using the Kansas Nutrient Utilization Plan on crop yield, yield components, and crop nutrient uptake. The study was conducted for 10 yr (1999 through 2008) near Tribune, KS. There were 10 treatments: three levels of cattle manure and swine effluent (P, N, and 2N), three levels of N fertilizer (N 1=56, N 2=112, and N 3=168 kg N ha -1), and an untreated control. Corn ( Zea mays L.) grain and stover yields, yield components, and water use were measured. In all but 2 yr, all treatments significantly increased grain yield compared with the control and the lowest inorganic N rate. Mean corn grain yield over the years from the Cattle N and P, Swine N and P, and inorganic N 2 and N 3 treatments were about 2*, 1.8*, and 1.9* greater than the untreated control, respectively. Grain nutrient content and water productivity were consistently higher for the cattle manure treatments and the inorganic N 2 and N 3 treatments. However, grain yield and nutrient uptake did not differ among rates of cattle manure and swine effluent application. We concluded that using the lower application rate based on either N or P from the Kansas Nutrient Utilization Plan was sufficient to achieve optimal crop yield and water productivity.
  • Authors:
    • Vanhie,M.
    • Deen,W.
    • Bohner,H.
    • Hooker,D. C.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: Many soybean [ Glycine max (Merr.)] growers in northern climates are reverting back to some tillage based on perceptions that increasing corn residues interfere with no-till (NT) soybean performance. Field trials were established in southern Ontario, Canada, to investigate the impact of corn residues on soybean among seven tillage strategies (NT, stalk chop, vertical tillage (VT) twice in the fall, fall and spring VT, fall disc plus spring cultivate, fall disc plus fall cultivate, and fall plowed plus spring cultivate), three corn residue removal treatments (none, intermediate, and nearly complete), and two planters (row-unit and drill). Overall, soybean yields were not different between NT and plowed systems, despite delayed development, and cooler/wetter seedbeds where corn residue was not removed. Shallow tillage after corn harvest did not increase yields from NT alone. Removal of corn residue did not increase soybean yields when averaged across tillage systems. However, NT yield was lowered by 0.36 Mg ha -1 when corn stalks were chopped in the fall, but only in the drill-planted treatments. This result was significant since many farmers have purchased corn combine heads that chop stalks in an attempt to manage residue. Soybean planted with a row-unit planter yielded 0.13 Mg ha -1 higher compared to a drill when averaged across tillage-residue treatments; differences between planters were higher when contending with high amounts of corn residue or an uneven soil surface at planting. Our results show that shallow tillage and/or physically removing corn residue did not improve soybean yield compared to NT alone.
  • Authors:
    • Wang,Jinzhou
    • Wang,Xiujun
    • Xu,Minggang
    • Feng,Gu
    • Zhang,Wenju
    • Lu,Chang'ai
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 102
  • Issue: 3
  • Year: 2015
  • Summary: Straw has been commonly incorporated to maintain soil fertility and crop productivity in China, but effects of long-term straw incorporation on crop yield, soil organic carbon (SOC) and total nitrogen (TN) have not been thoroughly evaluated. Thus, this study analyzed data collected in long-term (> 10-year) trials across the major agricultural zones of China. Across the trials, relative to straw removal, straw return significantly increased crop yield, SOC and TN (by 7.0, 10.1 and 11.0 %, respectively). In some trials with winter wheat in northern China, straw return reduced yield by 0.6-7.1 %. The effects of straw return on SOC and TN were not significantly affected by experimental duration, land use type and cropping system, but positively and linearly related to the inputs of straw-C and -N, respectively. Interestingly, SOC and TN responses to straw return were decoupled in upland and upland-paddy soils in China, but not in paddy soils. Mean values of straw-C sequestration efficiency (7.7, 10.3 and 9.4 %, under corn, wheat and rice, respectively) indicate that 100 % straw return could increase SOC by 281.7 Tg C in 18 years (the mean experimental period of the considered studies) in China. Our analyses demonstrate that straw return is an effective practice for sustaining crop productivity and soil fertility in large parts of China, but site-specific factors should be considered.
  • Authors:
    • Wegner,B. R.
    • Kumar,S.
    • Osborne,S. L.
    • Schumacher,T. E.
    • Vahyala,I. E.
    • Eynard,A.
  • Source: Soil Science Society of America Journal
  • Volume: 79
  • Issue: 4
  • Year: 2015
  • Summary: Excessive removal of crop residue has been shown to degrade soil organic carbon (SOC), and hence soil quality. Our objective was to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators. The experiment was conducted on a silty clay loam soil with and without a cover crop following three residue removal treatments. The low residue removal (LRR) treatment consisted of harvesting corn grain, leaving all other plant materials on the soil surface. Medium residue removal (MRR) consisted of harvesting grain, then chopping, windrowing and baling the remaining residue. The high residue removal (HRR) consisted of cutting the stalks 0.15 m from the ground and removing essentially all above-ground biomass. Crop residue removal significantly impacted measured soil properties including SOC, but cover cropping had minimal effects. The LRR treatment resulted in higher SOC concentrations and increased aggregate stability compared with other treatments. Residue removal significantly impacted the microbial activity as measured by hydrolysis of fluorescein diacetate (FDA). This study confirmed that HRR rates lead to SOC decomposition and adversely affect soil properties and soil quality. Soil conservation and emerging uses for crop residues must be balanced. Therefore, before making any decision to harvest crop residues, it is essential to have accumulated more C in the residue and supplemental cover crops than is needed to maintain equilibrium SOC levels. © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA. All rights reserved.
  • Authors:
    • Woli,K. P.
    • Ruiz-Diaz,D. A.
    • Kaiser,D. E.
    • Mallarino,A. P.
    • Sawyer,J. E.
  • Source: Agronomy Journal
  • Volume: 107
  • Issue: 5
  • Year: 2015
  • Summary: An on-farm study was conducted in Iowa from 2004 to 2006 at 18 sites to evaluate corn ( Zea mays L.) grain yield (GY) and soil- and plant-test responses to poultry manure (PM) nutrient application at the field scale. A control and two target PM rates based on total N (PM-N) were applied in randomized field-length strips with three replications. Corn GY responded positively to PM applications. While N, P, and K plant and soil tests were related to PM nutrient rates, there was considerable variation, and relationships were probably influenced by the multiple applied nutrients. Soil-test P and soil-test K across sites increased linearly with increasing PM total P and K rates and with large increases from the high rates. This confirms high P and K crop availability. Grain yield responses to PM decreased linearly with increasing leaf chlorophyll meter (CM) and late spring soil NO 3-N test (LSNT) values but were not related to end-of-season lower corn stalk NO 3-N test values. No N test had a plateau relationship with GY, suggesting no excess N supply despite large PM-N rates. This confirms low first-year PM-N availability. The relationship between CM and LSNT indicated a critical LSNT value at 24 mg kg -1, similar to that from previous small-plot research. This field-scale study showed that PM is a valuable nutrient resource. However, due to PM multinutrient content and differences in availability, the nutrient causing GY and plant- or soil-test results often cannot be clearly identified and results need careful interpretation for reliable use.
  • Authors:
    • Gong,Daozhi
    • Hao,Weiping
    • Mei,Xurong
    • Gao,Xiang
    • Liu,Qi
    • Caylor,Kelly
  • Source: PLoS ONE
  • Volume: 10
  • Issue: 8
  • Year: 2015
  • Summary: Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L.) fields under the traditional non-mulching with flat tillage (CK) and partial plastic film mulching with furrow-ridge tillage (MFR) on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE) of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI) and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3 degrees C and +4.3%) top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m(2) than CK. However, after considering carbon in harvested grain (or aboveground biomass), there is a slight higher carbon sink (or a stronger carbon source) in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.
  • Authors:
    • Mereu,Valentina
    • Carboni,Gianluca
    • Gallo,Andrea
    • Cervigni,Raffaello
    • Spano,Donatella
  • Source: Climatic Change
  • Volume: 132
  • Issue: 2
  • Year: 2015
  • Summary: Climate change impact on the agricultural sector is expected to be significant and extensive in Sub-Saharan Africa, where projected increase in temperature and changes in precipitation patterns could determine sensible reductions in crop yields and concerns for food security achievement. This study presents a multi-model approach to analysing climate change impacts and associated risks for staple food crops in Nigeria. Previous attempts to evaluate climate change impacts in Nigeria had mainly focused on a reduced number of crops, with analysis limited to single experimental fields or specific areas, and in many cases considering only a limited number of climate models. In this work, crop simulation models implemented in the DSSAT-CSM software were used to evaluate climate change impacts on crop production in different Agro-Ecological Zones, considering multiple combinations of soils and climate conditions, varieties and crop management. The climate impact assessment was made using an ensemble of future climate projections, to include uncertainty related to climate projections. Even if precipitations could increase in most parts of Nigeria, this is not likely to offset the crop yield reduction due to the increase in temperatures, particularly over the medium-term period (2050), with yield decreases projected especially for cereals. The short-term effects are more uncertain and yields for cassava and millet might actually increase by 2020. Moreover, yield reductions are only partially mitigated by the direct effect of increased CO2 atmospheric concentration enhancing crop yield. In both periods and for all crops, there is a higher risk that crop yields may fall below the actual risk threshold.
  • Authors:
    • Rosas,Francisco
    • Babcock,Bruce A.
    • Hayes,Dermot J.
  • Source: Climatic Change
  • Volume: 132
  • Issue: 2
  • Year: 2015
  • Summary: Farmers may choose to apply nitrogen fertilizer at a rate that exceeds the average ex post agronomically optimal rate when the yield response to nitrogen varies across growing seasons. Negative environmental consequences such as nitrous oxide (N2O) emissions and/or water pollution can result when all the applied nitrogen is not needed by the crop. Here we consider a nonlinear market instrument targeting farmers' nitrogen use, and by solving for the optimal nitrogen reduction using a model of expected utility of farm profits, we evaluate the induced N2O emission reductions that are consistent with the instrument introduced. The market instrument is nonlinear because of the expected nonlinear relationship between N2O and nitrogen application rates. Our simulations show that, in cases where farmers apply N at rates which exceed recommendations and the N2O response is likely to be non-linear, payments will induce participation in the program and will have a significant impact on both expected and actual N2O emissions without significantly harming expected or actual yields. Failure to consider this nonlinearity would deviate the attention away from N2O pollution because it would require large N reductions (and crop yields) to achieve equivalent N2O abatement.