Agronomic Inputs Research Articles

Know Your Community: Gaining Access to Agronomic Inputs

CSA NewsVolume 62, Issue 6 p. 21-21 Membership Know Your Community: Gaining Access to Agronomic Inputs Stella Salvo, Stella Salvo presiding leader, Gaining Access to Agronomic Inputs Community of ASASearch for more papers by this author Stella Salvo, Stella Salvo presiding leader, Gaining Access to Agronomic Inputs Community of ASASearch for more papers by this author First published: 01 June 2017 https://doi.org/10.2134/csa2017.62.0619Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume62, Issue6June 2017Pages 21-21 RelatedInformation

Fertilizing growth: Agricultural inputs and their effects in economic development

This paper estimates the role of agronomic inputs in cereal yield improvements and the consequences for countries' processes of structural change. The results suggest a clear role for fertilizer, modern seeds and water in boosting yields. We then test for respective empirical links between agricultural yields and economic growth, labor share in agriculture and non-agricultural value added per worker. The identification strategy includes a novel instrumental variable that exploits the unique economic geography of fertilizer production and transport costs to countries' agricultural heartlands. We estimate that a half ton increase in staple yields generates a 14 to 19 percent higher GDP per capita and a 4.6 to 5.6 percentage point lower labor share in agriculture five years later. The results suggest a strong role for agricultural productivity as a driver of structural change.

Cost and income structure of sweet corn (Zea mays saccharata Sturt.) cultivation as influenced by different agronomic inputs

Cost and income structure of sweet corn (<i>Zea mays saccharata</i> Sturt.) cultivation as influenced by different agronomic inputs

Rebel Capacity and Randomized Combat

Classic and modern theories of rebel warfare emphasize the role of unexpected attacks against better equipped government forces. We test implications of a model of com-bat and information-gathering using highly detailed data about Afghan rebel attacks, insurgent-led spy networks, and counterinsurgent operations. Timing of rebel operations responds to changes in the group’s access to resources, and main effects are significantly enhanced in areas where rebels have the capacity to spy on and infiltrate military installations. Results are supplemented with numerous robustness checks as well as a novel IV approach that uses machine learning and high frequency data on local agronomic inputs. Consistent with the model, shocks to labor scarcity and government surveillance operations have the opposite effect on attack timing. In addition, we investigate the impact of attack timing on battlefield effectiveness and find that it reduces soldier efficiency during missions to ‘find and clear’ roadside bombs and increases bomb-related casualties to government troops.

Irrigation water productivity is more influenced by agronomic practice factors than by climatic factors in Hexi Corridor, Northwest China.

Quantifying the influence of driving factors on irrigation water productivity (IWP) is vital for efficient agricultural water use. This study analyzed contributions of agronomic practice and climatic factors to the changes of IWP, based on the data from 1981 to 2012 in Hexi Corridor, Northwest China. Cobb-Douglas production functions were developed by the partial least squares method and contribution rates of the driving factors were calculated. Results showed that IWP and its driving factors increased during the study period, with different changing patterns. IWP was significantly correlated with the agronomic practice factors, daily mean temperature and solar radiation of the crop growing period. The agronomic practice factors including irrigation, fertilization, agricultural film, and agricultural pesticide contributed 20.6%, 32.8%, 42.3% and 11.1% respectively to the increase of IWP; and the contribution rates of the climatic factors, i.e. daily mean temperature and solar radiation, are −0.9% and 0.9%. And the contributions of these factors changed in different sub-periods. It is concluded that agronomic practice factors influenced IWP much more than climatic factors. The improvement of IWP should rely on advanced water-saving technology and application of optimum (need-based) fertilizer, agricultural film and pesticide, ensuring efficient use of agronomic inputs in the study area.

Dynamics of Microbial Functional Groups in Rhizosphere of Spring Barley

Plant rhizosphere is the portion of soil which is in direct contact with the plant roots. From the microbiological point of view, this area is characterized by strong dynamic of functional groups with high specificity towards the substrate available. Spring barley is a crop with high requirements to the composition of the microflora in the rhizosphere, disturbances produced by agronomic inputs affecting the stability of rhizospheric contact interfaces and ultimately the plant growth. Analysis of changes within the microbial community was carried out with the purpose of defining the disruptive impact of mineral inputs and potential of zeolite to reduce these disruptions. Microbial functional groups were analyzed on the basis of the CO2 export under the specific conditions of soil inoculation on specific substrates over a time period of incubation. Microresp detection plates allow evaluation of a large number of samples under identical conditions of inoculation and the establishment of dynamics of the entire microbial community. The dynamics of the entire microbial communities (basal respiration) is stimulated to increase in case of unilateral application of zeolite and zeolite as a buffer for urea fertilization. General growth trend of microbial communities follows proportional the associated application of zeolite with urea, the most powerful non-symbiotic nitrogen fixation processes being stimulated by this combination of fertilizers. Simultaneously, an increase in the dynamics of denitrifiers was observed, also the decomposition of lignin and cellulose and biological crust formation due to the proliferation of cyanobacteria. Rhizosphere of barley plants is characterized by the presence of actinomycetes as dominant in functional microbial community of all experimental variants analyzed with a high capacity for biological degradation and raised mineralization of organic matter.

Effects of soil physical and chemical parameters, and farm management practices on arbuscular mycorrhizal fungi communities and diversities in coffee plantations in Colombia and Mexico

Arbuscular mycorrhizal fungi (AMF) are essential for growth of coffee plants in acidic and phosphate deficient soils in Central and South America. We investigated the species richness of Glomeromycotean fungi in 9–13 years old coffee plantations in Colombia and Mexico. Fungal species richness was related to physical and chemical soil factors, soil aggregate stability, and farm management practices. Using morphological spore characteristics 85 AMF species were found. AMF species similarity within the plantations was 62–73 %, and the most regularly AMF species found in both countries were: Acaulospora mellea, Acaulospora spinosa, Ambispora fennica, Diversispora aurantia, Dominikia aurea, Glomus brohultii, Rhizoglomus clarum and Rhizoglomus intraradices. In both countries species richness was differently influenced by agronomic management intensity and soil parameter. In Colombia, where soils were more fertile with higher organic matter and soil pH than in Mexico, soil parameter explained the variations in species diversity, while in Mexico, agronomic management intensities explained the variations in species richness among sites. Soil aggregate stability slightly explains the AMF species richness in Colombia and Mexico. It can be concluded that the Glomeromycotean species richness is very high in older coffee plantations in Colombia and Mexico, and that agronomic inputs have positive effects on species richness in very acidic soils with lower organic matter contents, while in more fertile soils like in Colombia, soil parameter define more the AMF richness.

Sugars Production for Green Chemistry from 2nd Generation Crop (Arundo donax L.): A Full Field Approach.

Arundo donax L. (giant cane) is a suitable feedstock for sugar production because of its high biomass yield and low agronomic input requirement. Eight A. donax clones were studied at full field scale for sugars production. 1-ethyl-3-methylimidazolium acetate - [CCim][OAc] - and enzymatic treatments were used to obtain the sugars. Highest glucose yields were obtained for pretreatment performed at 160 °C for 3 hours, with glucan conversion yields from 40.8 % to 76.2 % for most productive A. donax clones (AD10 and AD 20). Differences in cell wall structure measured by micropore surface area (pores of 0.3 - 1.5 nm) explained both ionic liquids and enzymatic performances of clones. Structural differences were due to the guaiacyl (G) and syringyl (S) units that determined different lignin cross-linking affecting cell wall microporosity and so enzyme accessibility. Total glucose and xylose yields (11 Mg Ha and 4.84 Mg Ha, clone AD20), were impressive and about 3.5 to 4.5 times more than those obtainable from switchgrass and corn stover.

Investigating input combinations for field pea production

Field peas are an important pulse crop for Canadian Prairie farmers, accounting for approximately 3,650,000 seeded ac in 2015. The objective of the study was to determine (1) which individual agronomic inputs contribute most to field pea yield, (2) which combination of inputs produces the highest yield and economic return, and (3) how plant population, leaf and stem disease, crop maturity, and seed quality are affected by input interactions. Earn 0.5 CEUs in Crop Management by reading this article and taking the quiz at www.certifiedcropadviser.org/certifications/self‐study/787.

Evaluating Intercropping (Living Cover) and Mulching (Desiccated Cover) Practices for Increasing Millet Yields in Senegal

Located within the Sahel region, Senegal faces several agricultural production challenges. Limited rainfall, poor soil fertility, and insufficient agronomic inputs all contribute to low pearl millet [Pennisetum glaucum (L.) R. Br.] yields. This study was initiated to assess the potential for increasing millet yields through intercropping (living cover) and mulching (desiccated cover) practices. During the 2013 and 2014 growing seasons, pearl millet was intercropped with cowpea [Vigna unguiculata (L.) Walp.], mungbean [Vigna radiata (L.) Wilczek], or grown under mulch (neem [Azadirachta indica] leaves applied at 2 t ha−1). Field trials were conducted at two sites within Senegal's central millet–peanut (Arachis hypogaea L.) basin, in Bambey (14°41′38″ N, 16°28′12″ W) and Thiés (14°45′45″ N, 16°53′14″ W). Soil moisture and plant N (based on the normalized difference vegetation index [NDVI]) were measured in addition to yield. When intercropped with a legume, millet grain yields increased up to 55% compared to millet alone. The combined grain yields under intercropping (millet + legume) were always higher than yields of millet alone, up to 67% in Bambey. Mulching increased soil moisture up to 14%, with yield increases of up to 70% over millet with no mulch. Plant N increased in both intercropped and mulched millet, with NDVI increases up to 21% with mulch and 16% when grown with a legume (prior to flowering). These yield increases were achieved using resources that are available and affordable to small‐scale producers in the region (seeds and mulch), and did not require the addition of fertilizer inputs.Core Ideas Intercropping millet with cowpea or mungbean was found to increase millet grain yield compared to millet that was grown alone. Yield increases as high as 55% were recorded. Increasing ground cover through mulching of millet was found to significantly increase soil moisture compared to millet grown with no additional ground cover. Soil moisture increased up to 14% in mulched soils compared to unmulched soils. Intercropping millet with a legume (cowpea or mungbean) always resulted in a higher combined yield than growing either the millet or the legume by itself.

Environmental and economic benefits of variable rate nitrogen fertilization in a nitrate vulnerable zone

Agronomic input and management practices have traditionally been applied uniformly on agricultural fields despite the presence of spatial variability of soil properties and landscape position. When spatial variability is ignored, uniform agronomic management can be both economically and environmentally inefficient. The objectives of this study were to: i) identify optimal N fertilizer rates using an integrated spatio-temporal analysis of yield and site-specific N rate response; ii) test the sensitivity of site specific N management to nitrate leaching in response to different N rates; and iii) demonstrate the environmental benefits of variable rate N fertilizer in a Nitrate Vulnerable Zone. This study was carried out on a 13.6ha field near the Venice Lagoon, northeast Italy over four years (2005–2008). We utilized a validated crop simulation model to evaluate crop response to different N rates at specific zones in the field based on localized soil and landscape properties under rainfed conditions. The simulated rates were: 50kgNha−1 applied at sowing for the entire study area and increasing fractions, ranging from 150 to 350kgNha−1 applied at V6 stage. Based on the analysis of yield maps from previous harvests and soil electrical resistivity data, three management zones were defined. Two N rates were applied in each of these zones, one suggested by our simulation analysis and the other with uniform N fertilization as normally applied by the producer. N leaching was lower and net revenue was higher in the zones where variable rates of N were applied when compared to uniform N fertilization. This demonstrates the efficacy of using crop models to determine variable rates of N fertilization within a field and the application of variable rate N fertilizer to achieve higher profit and reduce nitrate leaching.

Global agricultural intensification during climate change: a role for genomics.

SummaryAgriculture is now facing the ‘perfect storm’ of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic‐assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change.

Peanut shell biochar improves soil properties and peanut kernel quality on a red Ferrosol

Biochar has excellent potential to improve crop yield and quality, but its effects vary depending on soil type and agronomic inputs (e.g., irrigation and fertiliser). In this study, we investigate the effects of biochar on peanut productivity and crop quality under different irrigation and fertilisation regime in red Ferrosols. We applied peanut shell biochar (9.2 t ha−1) on a red Ferrosol under field conditions to examine the effects of biochar, irrigation, fertiliser and their interactions on soil properties and yield and kernel quality of the peanut variety ‘Middleton’. Biochar application improved kernel quality by increasing the fraction of the highest commercial grade kernels (grade ‘Jumbo’) but did not affect photosynthesis and yield of peanut. Biochar application also increased soil total C (TC), total nitrogen (TN) and C/N ratio, and changed soil C and N stable isotope composition. Soil K and Zn content was higher in biochar treatments, which partially explains the observed kernel grade improvement. Fertilisation did not improve peanut performance, and irrigation generally had a negative effect on crop yield and physiology, but these data were compromised by high rainfall during cropping. There were few interactions among biochar, irrigation and fertiliser treatments. Peanut shell biochar improves soil organic C, nutrient availability and peanut kernel quality under different irrigation and fertiliser rate regimes in field conditions.

Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum).

Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs) and a MYB (PvMYB46A), for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

Alternative storage systems of Arundo donax L. and characterization of the stored biomass

Arundo donax L. has received much attention from researchers as biomass crop because of its vigorous growth, high productivity and low agronomic inputs requirements. Once harvested, the chopped biomass of A. donax L. may be stored for a variable period according to energy demand or logistic reasons. As consequence of storage, the chopped biomass may undergo processes of degradation that can compromise the energy yield of the product and the economic convenience of the cultivation.In the view of preserving the A. donax L. biomass for producing different kind of energy, such as bio-ethanol, biogas, and fuel for combustion, the aim of this study was to investigate, in small-scale, different storage systems assessing the dynamics of storage and their effects on energy losses and fuel quality. The work has included different studies, such as (i) the monitoring of heat development, moisture content and dry matter losses, (ii) the analysis of polymeric compounds and combustion performances. Results indicate that according to the storage method adopted, the conservation of the product can be significantly influenced, with clear impacts on its energy potential. Polymeric composition changed after storage according to the method used, while energetic characteristics were not remarkably affected.

A comparison of farming practices and performance for wheat production in Haryana, India

An extensive stratified survey was conducted in two different wheat growing seasons in all districts of Haryana (India) to evaluate current agronomic practices and assess performance in wheat production with the purpose of identifying where farmers can make further changes in practices. The survey involved 116 villages (927 farmers) in 2008 and 103 villages (823 farmers) in 2010. Different sized farming operations from each village were surveyed to represent all socio-economic categories of farmers. Agronomic inputs (tillage method, fertilizer practice, variety choice, time of sowing, irrigation, and rotation practice) and yield data are presented as mean data, and individual farmer's information is represented by regression tree (RT) analysis to highlight primary associations between cropping management and wheat yield and the technical efficiency (TE) measure. TE was calculated using the key agronomic variables obtained from the survey, and the farms with the highest TE values were assessed as having the superior ‘best practice’ technology. In the districts where the rice–wheat rotation was adopted, there was an overall higher level of TE. Where rice–wheat rotation is the main cropping practice (for example in Kaithal and Kurukshetra), many of the farmers have adopted zero tillage farming methods, with one third of farmers in Kaithal using zero tillage for planting wheat. In contrast, in Sirsa district where cotton was favoured by the farmers as their monsoon season crop, there were no farms where zero tillage was practised. Also, there was also no zero tillage farming where the pearl millet/cluster bean rotation was used as the monsoon season crop. In most cases farmers use a two applications of nitrogen fertilizer applied post-emergence, particularly in the rice–wheat and cotton–wheat districts. The survey also showed that application of potassium fertilizer and use of zinc is regionally specific and this is consistent with the soil maps that show the potential for deficiency of these nutrients in Haryana districts. Sowing in the rice–wheat districts was mostly at the recommended time in early November. The highest number of irrigations occurred in the districts using the pearl millet–wheat and cluster bean–wheat rotations where sprinkler irrigation is the main application practice. The analysis of TE provides a useful comparison when the 5 different farm size categories are separated. There was no difference in TE with farm size, suggesting the message concerning best practice for wheat production is available to and adopted by farmers irrespective of scale of operation. This analysis highlights where extension messages could be focused, whether for zero tillage in the non-rice districts, management of macro-nutrients, or the targeted use of micronutrients.

New energy crop giant cane (Arundo donax L.) can substitute traditional energy crops increasing biogas yield and reducing costs

Giant cane is a promising non-food crop for biogas production. Giant cane and corn silages coming from full-scale fields were tested, in mixtures with pig slurry, for biomethane production by a continuous stirred tank lab-scale-reactor (CSTR) approach. Results indicated that giant cane produced less biomethane than corn, i.e. 174±10Nm3CH4Mg−1TS−1 and 245±26Nm3 CH4Mg−1TS−1, respectively. On the other hand, because of its high field biomass production, the biogas obtainable per Ha was higher for giant cane than for corn, i.e. 12,292Nm3 CH4Ha−1 and 4549Nm3CH4Ha−1, respectively. Low energetic and agronomic inputs for giant cane cultivation led to a considerable reduction in the costs of producing both electricity and biomethane, i.e. 0.50€Nm−3CH4−1 and 0.81€Nm−3CH4−1, and 0.10€kWhEE−1 and 0.19€kWhEE−1 for biomethane and electricity production, and for giant cane and corn mixtures respectively.

Decimal growth stages for precision wheat production in changing environments?

AbstractThe utility of the decimal growth stage (DGS) scoring system for cereals is reviewed. The DGS is the most widely used scale in academic and commercial applications because of its comprehensive coverage of cereal developmental stages, the ease of use and definition provided and adoption by official agencies. The DGS has demonstrable and established value in helping to optimise the timing of agronomic inputs, particularly with regard to plant growth regulators, herbicides, fungicides and soluble nitrogen fertilisers. In addition, the DGS is used to help parameterise crop models, and also in understanding the response and adaptation of crops to the environment. The value of the DGS for increasing precision relies on it indicating, to some degree, the various stages in the development of the stem apex and spike. Coincidence of specific growth stage scores with the transition of the apical meristem from a vegetative to a reproductive state, and also with the period of meiosis, is unreliable. Nonetheless, in pot experiments it is shown that the broad period of booting (DGS 41–49) appears adequate for covering the duration when the vulnerability of meiosis to drought and heat stress is exposed. Similarly, the duration of anthesis (61–69) is particularly susceptible to abiotic stresses: initially from a fertility perspective, but increasingly from a mean grain weight perspective as flowering progresses to DGS 69 and then milk development. These associations with DGS can have value at the crop level of organisation: for interpreting environmental effects, and in crop modelling. However, genetic, biochemical and physiological analysis to develop greater understanding of stress acclimation during the vegetative state, and tolerance at meiosis, does require more precision than DGS can provide. Similarly, individual floret analysis is needed to further understand the genetic basis of stress tolerance during anthesis.

Crop management modifies the benefits of insect pollination in oilseed rape

In a factorial field plot experiment, high and low levels of inorganic nitrogen and of insect pollinators visiting the crop were manipulated and their combined effects on oilseed rape yield were quantified. A third factor was also included, testing whether different cultivars responded differently to the tested factors. Insect pollination was required to reach high yield and seed quality (oil content). Final benefits of pollination service were, however, greatly modified by cultivar, where the seed yield of the open-pollinated cultivar largely depended on insect pollination whereas the two hybrid cultivars did not. A near significant interaction between nitrogen input and insect pollination was also found, i.e. benefits to crop yield from insect pollination seemed to increase with decreased nitrogen levels. The differential response of the three cultivars suggested opportunities to use cultivars that are less dependent on insect pollination in landscapes where this service has been deteriorated. Increased access of nitrogen seems to partly compensate yield losses from poor insect pollination. Integrating conservation, environmental and agronomic sciences is therefore crucial to sustain agriculture productions through optimized management of agronomic inputs and biodiversity-based ecosystem services.

Current Research on Plant-Growth Promoting Rhizobacteria in Latin America: Meeting Report from the 2nd Latin American PGPR Workshop

Crop performance depends, to a large degree, on biological activities taking place in the root environment. By the early twentieth century, it was already recognized that plants exert key effects on the soil space just outside the root surface. This led to the concept of the rhizosphere, that is, the portion of the soil that is directly influenced by the root (Hiltner 1904). The rhizosphere contains diverse microorganisms that induce beneficial, neutral, or deleterious effects on plant growth. The beneficial rhizosphere bacteria were deemed plant-growth promoting rhizobacteria (PGPR) (Kloepper and Schroth 1978). The rhizosphere was then recognized to be an active microbial habitat with complex and multitrophic biological interactions among microbes and eukaryotic organisms, and focused studies on these interactions began. The applications of such knowledge were of direct economical relevance given that PGPRs may be utilized as agronomic inputs to increase crop yields. This gave rise to a community of scientists interested in elucidating the mechanisms displayed by PGPR species and understanding the role of the plant in shaping the microbial community of the rhizosphere. In parallel, a number of private companies started to commercialize PGPR-based products for a range of agronomical applications worldwide, with Latin American countries taking the lead in this field. With these interests in mind, the International PGPR Workshop was first held in Canada in 1987 and since then, the workshop has been held every 3 years at different locations around the world (Switzerland, Australia, Japan, Argentina, India, The Netherlands, USA and Colombia). With the selection of a Latin American venue for the last international PGPR workshop and based on a regional demand for exchange of basic and applied information about the biology of PGPR and its applications, Quirama (Medellin, Colombia) hosted the 1st official Latin American PGPR meeting as a branch of the International edition. At that time, it was decided that the Latin American PGPR would be held every two years, and that the next venue would be Argentina.