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The effects of soil type and organic material quality on the microbial biomass and functional diversity of cropland soils were studied in a transplant experiment in the same climate during a 1-year field experiment. Six organic materials (WS: wheat straw, CS: corn straw, WR: wheat root, CR: corn root, PM: pig manure, CM: cattle manure), and three contrasting soils (Ferralic Cambisol, Calcaric Cambisol and Luvic Phaeozem) were chosen. At two time points (at the end of the 1st and 12th months), soil microbial biomass carbon (C) and nitrogen (N) (MBC and MBN) and Biolog Ecoplate substrate use patterns were determined, and the average well color development and the microbial functional diversity indices (Shannon, Simpson and McIntosh indices) were calculated. Organic material quality explained 29.5–50.9% of the variance in MBC and MBN when compared with the minor role of soil type (1.4–9.3%) at the end of the 1st and 12th months, and C/N ratio and total N of organic material were the main parameters. Soil properties, e.g., organic C and clay content were the predominant influence on microbial functional diversity in particular at the end of the 12th month (61.8–82.8% of the variance explained). The treatments of WS and CS significantly improved the MBC and microbial functional diversity indices over the control in the three soils in both sampling periods (P < 0.05). These results suggest that the application of crop straw is a long-term effective measure to increase microbial biomass, and can further induce the changes of soil properties to regulate soil microbial community. [ABSTRACT FROM AUTHOR]

Silage maize (Zea mays L.) is the dominating energy crop for biogas production due to its high biomass yield potential, but alternatives are currently being discussed to avoid environmental problems arising from maize grown continuously. This study evaluates the productivity and resource use efficiency of different bioenergy crops and cropping systems using experimental and simulation modelling derived data. The field experiment consisted of two years, two sites differing in soil texture and soil water availability, different cropping systems and increasing nitrogen (N) supply. Continuous (two years) perennial ryegrass and two crop rotations including winter cover crops (double cropping system) and combining C4 and C3 crops were compared with continuous maize (maize--maize). The productivity of the crops and cropping systems in terms of dry matter (DM) yield was analyzed with respect to the fraction of light interception and light use efficiency (LUE). In addition, water use and water use efficiency (WUE), N uptake, and N use efficiency (NUE) were quantified. DM yield of the double cropping system was similar to that of continuous maize, due to a prolonged leaf area duration, compensating for the intrinsic lower LUE of C3 crops. Perennial ryegrass was less productive than the other crops/cropping systems. Nitrogen uptake and consequently N demand of perennial ryegrass and the C3 crops of the crop rotations were higher than for maize--maize. Groundwater recharge was mainly site-dependent, but was at both sites higher for maize than for the crop rotations or the perennial ryegrass system. Our results indicate that, in terms of biomass productivity, optimized rotations are feasible alternatives to maize--maize, but trade-offs exist in terms of water and N use efficiency. [ABSTRACT FROM AUTHOR]

Development of semi-dwarf wheat (Triticum aestivum) and rice (Oryza sativa) led to increased yields and agronomic efficiencies with less lodging. While these short-stature cereals have become common in global crop production, commercial maize (Zea mays L.) hybrids remain tall. There is no information currently available on plant N uptake or yield responses to N timing for short stature maize hybrids. We tested three hypotheses on short-stature and tall maize hybrids 1) short-stature maize hybrids would have similar yield response to in-season N application compared to tall hybrids, 2) short-stature maize hybrids would have similar dry matter and N uptake patterns to tall hybrids, and 3) there would be significant partitioning differences between short-stature and tall hybrids in dry matter and N within the plants at multiple growth stages. In ten side-by-side field trials across eight site-years in the Midwestern USA, we tested the yield response and underlying nitrogen physiology of short-stature maize hybrids and tall comparators to split-rate N application. We show that split-rate application of 50% of the total N at mid-vegetative stages (V6) averaged 0.24 t ha−1 more grain yield across 10 field trials (positive yield response in 6 out of 10 trials) compared to a single 100% up-front N application, with the same pattern for short-stature and tall hybrids. In both hybrid statures, V6 N applications showed more frequent improvement in grain yield than V12 N applications. Total N uptake at maturity was not different between short-stature hybrids and their tall counterparts (p = 0.62). N partitioning differed between short-stature and tall hybrids; leaves in short-stature hybrids had 5% higher N concentration and 13% more N content in early vegetative development, stalks had 18–27% less dry matter and 5–25% less N content, depending on growth stage, while R1 ears averaged 18% more dry matter and N accumulation (p < 0.10 in all cases). At maturity short-stature hybrids had 4% higher harvest index and 3% higher N harvest index (p < 0.10). Based on these results, we expect that N management recommendations in short-stature maize hybrids would be similar to their tall counterparts, but that short stature mitigates logistical risk by providing more flexibility for in-season N applications. This study provides a unique, robust dataset on yield and physiological response to split-rate N treatments in commercially relevant maize hybrids. • Short stature in maize simplifies in-season N application and later crop management. • Split-rate N applications at V6 increased hybrid yields 60% of the time, with similar patterns for short-stature and tall hybrids. • Overall, short-stature maize yielded similarly to tall comparators. • Short stature led to greater partitioning of N and dry matter to the grain than tall hybrids. • Greater flexibility for in-season N fertilization in short-stature maize reduces in-season application risks. [ABSTRACT FROM AUTHOR]

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It is not yet clear whether the carbon released from biochar in the soil solution stimulates biological activities. Soluble fractions (AQU) from wheat and maize biochars, whose molecular content was thoroughly characterized by FTIR, 13 C and 1 H NMR, and high-resolution ESI-IT-TOF-MS, were separated in dilute acidic solution to simulate soil rhizospheric conditions and their effects evaluated on maize seeds germination activity. Elongation of maize-seeds coleoptile was significantly promoted by maize biochar AQU, whereas it was inhibited by wheat biochar AQU. Both AQU fractions contained relatively small heterocyclic nitrogen compounds, whose structures were accounted by their spectroscopic properties. Point-of-Zero-Charge (PZC) values and van Krevelen plots of identified masses of soluble components suggested that the dissolved carbon from maize biochar behaved as humic-like supramolecular material capable to adhere to seedlings and deliver bioactive molecules. These findings contribute to understand the biostimulation potential of biochars from crop biomasses when applied in agricultural production. [ABSTRACT FROM AUTHOR]

Silage maize (Zea mays L.) is the dominating energy crop for biogas production due to its high biomass yield potential, but alternatives are currently being discussed to avoid environmental problems arising from maize grown continuously. This study evaluates the productivity and resource use efficiency of different bioenergy crops and cropping systems using experimental and simulation modelling derived data. The field experiment consisted of two years, two sites differing in soil texture and soil water availability, different cropping systems and increasing nitrogen (N) supply. Continuous (two years) perennial ryegrass and two crop rotations including winter cover crops (double cropping system) and combining C4 and C3 crops were compared with continuous maize (maize–maize). The productivity of the crops and cropping systems in terms of dry matter (DM) yield was analyzed with respect to the fraction of light interception and light use efficiency (LUE). In addition, water use and water use efficiency (WUE), N uptake, and N use efficiency (NUE) were quantified. DM yield of the double cropping system was similar to that of continuous maize, due to a prolonged leaf area duration, compensating for the intrinsic lower LUE of C3 crops. Perennial ryegrass was less productive than the other crops/cropping systems. Nitrogen uptake and consequently N demand of perennial ryegrass and the C3 crops of the crop rotations were higher than for maize–maize. Groundwater recharge was mainly site-dependent, but was at both sites higher for maize than for the crop rotations or the perennial ryegrass system. Our results indicate that, in terms of biomass productivity, optimized rotations are feasible alternatives to maize–maize, but trade-offs exist in terms of water and N use efficiency.

Background and aims: Intercropping often produces more biomass than the average of the corresponding monocultures, particularly in sustainable, low-input agriculture. Characterizing plant-plant interactions is fundamental for a better understanding of the ecological functioning of intercropping. However, there is little information on whether mycorrhizal networks exhibit different effects upon intra- and interspecific plant interactions in intercropping systems. Methods: Microcosms with one inner and three outer compartments were used. The inner compartment was separated from the outer compartments by a 30-μm nylon mesh or a solid barrier or remained open to allow full interactions between plants grown in the different compartments, creating three treatments, namely −Roots−CMNs (solid barrier), −Roots+CMNs (mesh), and +Roots+CMNs (no barrier). Either faba bean ( Vicia faba) or maize ( Zea mays) was grown as the donor plant in the inner compartment. Maize was combined with maize, wheat ( Triticum aestivum) or the weed species foxtail ( Setaria viridis) as the neighboring plant species. Faba bean was combined with faba bean, maize, or foxtail. The low-P soil was inoculated with the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae or remained uninoculated. Results: In the absence of AMF, plant growth was restricted by P deficiency and root interactions did not significantly affect plant-plant interactions. The presence of AMF enhanced plant biomass (maize by 104.5 %, faba bean by 61.6 %) and nutrient (N and P) uptake. Significant overyielding occurred in treatments where roots and hyphal networks of all plant species intermingled. The weed (foxtail) was suppressed by interspecific interactions while maize and faba bean benefitted from a mycorrhizal network and the presence of intermingling roots. Conclusions: In low-P soils, mycorrhizal networks contribute to overyielding in intercropping by enhancing the biomass and nutrient uptake of the mycorrhiza-dependent plant species. The biomass depression of weed species by AMF and/or root interactions may have ecological implications in weed control in intercropping systems. [ABSTRACT FROM AUTHOR]

The key to optimizing alcohol production from cereals is a full understanding of the physiology and processing characteristics of different cereals. This study examined the maximum alcohol yields that can be obtained from wheat and maize using different processing technologies. Lower processing temperatures (85°C) resulted in high alcohol yields from wheat (a temperate crop), whereas higher processing temperatures (142°C) gave maximum alcohol yields from maize (a tropical crop). Similar trends were also observed when the spent grains from these cereals were processed using commercial enzymes. Mill settings were additional factors in influencing alcohol production. Wheat has the potential to produce higher alcohol yields when compared with maize, when residual biomass (i.e. spent grains) saccharification using selected commercial enzymes is taken into account. While this approach is not applicable for the Scotch whisky industry owing to strict legislation forbidding the use of exogenous enzymes, this is pertinent for bioethanol production to increase the alcohol yield obtained from both starch and lignocellulosic components of whole cereal grains. Wheat and maize processing temperatures and the use of processing aids are of potential economic benefit to bioethanol producers and to beverage alcohol producers seeking to understand the factors influencing the processing properties of different cereals. Copyright © 2015 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]