Perennial Systems Research Articles

Agri-environmental implications of N- and P-based manure application to perennial and annual cropping systems

Continuous manure application based on crop nitrogen (N) requirements could substantially increase field nutrient losses from croplands. Although phosphorus-based (P) manure application is an alternative, crops may suffer from potential microbial P immobilization and fixation of P in soil. A three-year study (2012–2014) was carried out in Manitoba, Canada, to evaluate the agronomic and environmental benefits and tradeoffs between N- and P-based liquid and solid swine manure applications on previously established (2009) annual (ACS) and perennial (PCS) cropping systems. The N-based solid manure produced greater aboveground biomass and grain yields of barley than the unfertilized control in the ACS. The N-based liquid manure produced greater biomass than the control in the PCS. Phosphorus-based treatments produced statistically similar canola oilseed grains as the N-based treatments. Seeding the PCS to canola in 2013 produced greater aboveground biomass yields than the ACS; however, the canola oilseed yields were not significantly different between the two systems. The N-based solid manure application increased Olsen P by approximately 30 mg kg−1 in both cropping systems during the three-year study period. Both N- and P-based liquid manure treatments and the N-based solid manure treatment lost significantly greater nitrate through leaching than the control in 2013, when most leaching losses occurred. Our study also showed that some of the environmental benefits of the perennial cropping system, such as reduced nitrate leaching, could be lost when converted to an annual cropping system.

Short-Term Mineralization of Belowground Biomass of Perennial Biomass Crops after Reversion to Arable Land

Little is known about the effect of perennial biomass crops (PBCs) removal on soil C dynamics. The belowground biomass (BGB) that is composed by plant belowground organs (PBO) such as rhizomes in the herbaceous PBCs and stumps in woody PBCs should be considered, together with fine roots (FR), as a huge input of exogenous organic matter (EOM) that is incorporated into the soil at the reversion. In this study, we mimic the incorporation of BGB of PBCs through a soil-residues incubation under controlled conditions to investigate the effects of adding FR and PBO (at real field rates) on soil C and N mineralization dynamics, and to understand decomposition controlling factors. A modified RothC model version, encompassing a better description of decomposable (DEOM) and resistant (REOM) pools, was fitted to C mineralization curves of respiration measured by CO2 evolution in incubated soil to quantify partitioning factors and decomposition rates of PBCs BGB components. After 1 month, PBO showed higher mineralization rates (498 µg CO2-C gsoil−1) than FR (196 µg CO2-C gsoil−1), with black locust having the highest amount of C respired (38% of added C). The emission peak occurred within 3 days from the beginning of the experiment for PBO and after 1 day for FR. Generally, according to the modified version of RothC model, PBO had higher proportion of REOM than FR, except for black locust. The decomposition constant rates from the optimized RothC model were higher for PBO (kDEOM: 20.9 y−1, kREOM: 12.1 y−1) than FR (kDEOM: 0.4 y−1, kREOM: 0.1 y−1), indicating that FR are less decomposable than PBO. The C/N ratio is not the main controlling factor of decomposition when residue N is not a limiting factor, while the availability of easily decomposable substrates (DEOM/REOM ratio) and cell-wall composition decomposition is a strong predictor of C and N mineralization of these EOM types. The explicit inclusion of crop-specific DEOM/REOM ratios within RothC or a similar soil C model will help to improve the predictions of long-term C sequestration trajectories (half-life > 30 years) associated with PBCs cultivation, especially when dismission of such perennial cropping systems is addressed.

Homogeneous land-use sequences in heterogeneous small-scale systems of Central Kenya: Land-use categorization for enhanced greenhouse gas emission estimation

The current understanding of the link between land management practices and GHG (greenhouse gas) emissions is limited in the small-scale farm sector of sub-Sahara regions due to insufficient or fragmented land-use data. Land-use categories recognized in the national GHG inventories in Kenya are coarse. Therefore, they do not adequately account for the diversity in small-scale land uses. Characterization of land-use and knowledge of key drivers of land-use change is necessary to improve national GHG inventories in the SSA (Sub-Sahara Africa) region. We implemented a cross-sectional survey to characterize land-use and determine factors which influenced changes in land use within small-scale farms of Tharaka-Nithi County, Kenya. We sampled 300 farmers using multistage sampling and collected crop sequence recall data at plot level for three years (seven seasons). We grouped crop sequences into clusters using the ‘TraMineR’ R package. We derived four clusters including banana, tea, and declining fallows (cluster 1, 19.2% of plots), cereal-legume systems (cluster 2, 55.1%), fodder (cluster 3, 11.7%) and coffee (cluster 4, 14.0%). We observed higher N application rates in perennial cropping systems, than in annual crops, including cereal-legume systems. We observed that farmers in higher potential agro-ecological zones, male-managed farms, with higher per capita land area, higher remittances and higher total house-hold incomes, were associated with a higher propensity to adjust crop enterprises, leading to more unstable land-use sequences. Contrariwise, farmers with higher education, credit access, secure land tenure, increasing slope, good soil fertility, and longer farming experiences recorded a lower propensity to adjust their land uses, resulting in more stable crop sequences. Farmer socio-demographic characteristics influenced land-use change, which is directly linked with soil GHG emissions. Our findings propose the adoption of Tier II GHG quantification approaches which disaggregate between annual and perennial crop enterprises. GHG emissions are likely to be more generalizable in stable perennial crop systems than annual systems. Thus, better disaggregation of GHG sampling in annual crop systems is needed due to high diversity in crop and soil fertility management, and the dynamic nature of C and N cycling in these systems.

Seed Size, Planting Depth, and a Perennial Groundcover System Effect on Corn Emergence and Grain Yield

The intensive corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices currently used in the Midwestern U.S. concern producers and stakeholders. The negative impact of these two-crop rotations on the environment affects water quality and soil erosion and increases flooding risks. Due to these concerns, cover crops and, specifically, perennial groundcover (PGC) cropping systems have gained greater interest. These perennial species have growing patterns compatible with corn and soybean, and can help rebuild the ecosystem while maintaining good cash crop yields. In addition, producers also are interested in the possible effect of seed size and planting depth on uneven emergence in corn. The successful adoption of PGC systems ultimately depends on the successful corn seedling emergence and consistent yield. The objective of the study was to understand the effects of seed characteristics and placement on emergence, grain yield, and grain quality in corn planted using a Kentucky bluegrass (Poa pratensis L.) (KBG)-PGC and a bare-soil cropping system and to determine grain quality attributes and grain moisture dry-down in a PGC field when compared to a conventional cropping system. Commercially-sized seed and seed sized in the laboratory to represent a narrower seed size distribution were planted in KBG-PGC and bare soil systems at two planting depths (3.18 and 6.35 cm). The two-year experiments were planted in a split-plot RCB design with four replications. Individual plants were flagged at emergence, and ears from each plant were harvested individually. Separating the seed lot into different size distributions did not affect seed germination under ideal (standard germination and speed of germination tests) or stressful (cold test) conditions. Seed size distribution also did not influence emergence rate and yield in a conventional tillage (bare soils) or KBG-PGC system. These results indicate that seed sizing specifications and seed size cutoffs currently used by seed companies are suitable for uniform emergence and maximum grain yield in both cropping systems. Seed placement was crucial to uniform emergence in both cropping systems, while seed size distribution did not play a role in emergence for either system. The PGC cropping system delayed seed corn emergence and reduced grain yields as much as 50%. This information is important for those producers considering adopting a PGC system because it demonstrates that uniform planting depth is more important than seed size distribution.

Progress Towards Perennial Grains for Prairies and Plains

Perennial grain crops have been proposed as environmentally sustainable alternatives to annual grain crop systems that currently dominate the world's major breadbaskets. Proponents emphasize the potential of perennial grains to mimic natural systems and thereby reduce soil erosion, nutrient losses, and degradation of soil quality although need for adequate grain yield is also recognized as a prerequisite for success. Here we assess progress since 2005 (16 y) towards development of perennial grain systems with sufficient productivity to be seen as competent alternatives to annual wheat on the prairies and plains of North America and Australia. Based on reports published in refereed journals, we see little evidence that yield of Intermediate Wheatgrass or perennial wheats have improved to the point they are viable alternatives. Slow progress is attributed to lack of minimum grain yield targets for economic viability, lack of designated target regions where perennial grains are most likely to be competitive against annuals, selection methods that focused on components of yield rather than yield per se (i.e. on an area basis), and relatively small R & D investment compared to resources given to genetic and agronomic improvement of major annual grain crops. Given current status, we conclude that perennial grains will require substantial R & D investment and several decades if they are to achieve sufficient yield potential and yield persistence to become more than a niche crop for upscale health food markets in wealthy countries.

A new bioenergy model that simulates the impacts of plant‐microbial interactions, soil carbon protection, and mechanistic tillage on soil carbon cycling

AbstractAdvancing our predictive understanding of bioenergy systems is critical to design decision tools that can inform which feedstock to plant, where to plant it, and how to manage its production to provide both energy and ecosystem carbon (C) benefits. Here, we lay the foundation for that advancement by integrating recent developments in the science of belowground processes in shaping the C cycle into a new bioenergy model, FUN‐BioCROP (Fixation and Uptake of Nitrogen‐Bioenergy Carbon, Rhizosphere, Organisms, and Protection). We show that FUN‐BioCROP can approximate the historical trajectory of soil C dynamics as natural ecosystems were successively converted into intensive agriculture and bioenergy systems. This ability relies in part on a novel tillage representation that mechanistically models tillage as a process that increases microbial access to C. Importantly, the impacts of tillage and feedstock choice also influence FUN‐BioCROP simulations of warming responses with no‐till perennial feedstocks, miscanthus, and switchgrass, having more C that is unprotected and susceptible to warming than tilled annual feedstocks like corn–corn–soybean. However, this susceptibility to warming is balanced by a greater potential for increases in belowground C allocation to enhance soil C stocks in perennial systems. Collectively, our model results highlight the importance of belowground processes in evaluating the ecosystem C benefits of bioenergy production.

Cropping management in a livestock-pasture-crop integration modifies microbial communities, activity, and soil health score.

Understanding indicators of soil health is crucial for developing agricultural systems that are sustainable and climate resilient. Labile soil carbon (C), microbial properties, and nutrient status are all incorporated into the Haney Soil Health Tool with the goal of summarizing several indicators into one index. Monthly soil samples from an integrated crop-livestock system in Central Texas were collected from 2017 to 2019. Fields represented a range of management practices, including cover crops, no-till, rotational grazing, and a native prairie remnant. Soil samples were analyzed for total C, water-soluble C, macro- and micronutrient content and bioavailability, and phospholipid fatty acids (PLFAs). Microbial activity was determined via a 24-h CO2 incubation. Soil health score, C, and PLFAs were well correlated with each other. The greatest total PLFA (219.5nmol g-1 soil) and organic C (54.3g kg-1 soil) were found in the native prairie, and the lowest were found in the unfertilized continuous-corn system (60.5nmol PLFAs g-1 soil and 24.0g organic C kg-1 soil). Of all agroecosystems, the perennial grazing system (soil health score, 24.7) was most similar to the native prairie (soil health score, 27.4), having high soil C and a large microbial community. Of the row cropping systems, the no-till system approached the perennial systems better than the conventional till and unfertilized conventional till (soil health score, 11.1 vs. 8.0 and 5.3, respectively). This study highlights the value of perennial grass grazing in agroecosystems and appropriate best management practices. Expanding this analysis to other sites may provide additional insight.

Field evidence for disequilibrium dynamics in preserved fluvial cross-strata: A record of discharge variability or morphodynamic hierarchy?

Bedforms preserved in the rock record can provide detailed information on the morphologies and hydrodynamics of ancient fluvial systems on Earth and other planets. Existing process–product relations for bedform preservation assume that fluvial cross strata reflect conditions under which bedforms were equilibrated with the prevailing flow, i.e., steady-state conditions. However, recent theoretical and experimental observations indicate that enhanced bedform preservation can occur in non-steady state, or disequilibrium, conditions, and it is currently unclear how prevalent disequilibrium dynamics are in preserved fluvial strata at outcrop scale. Here we explore whether steady-state assumptions are appropriate for ancient fluvial systems by evaluating the nature of bedform preservation in well studied fluvial deposits of three Upper Cretaceous (Turonian and Campanian) geologic formations in central Utah, USA: the Blackhawk Formation, Castlegate Sandstone, and Ferron Sandstone. In the field, we made systematic measurements of dune-scale cross-strata to quantify the extent to which preserved cross-sets reflect dune preservation in steady-state conditions. Across the three formations, consistently low coefficients of variation in preserved cross-set thicknesses of 0.25–0.5 are inconsistent with bedform preservation in steady-state conditions, and instead point to fluvial systems in which enhanced bedform preservation occurred in disequilibrium conditions.Enhanced bedform preservation in dune-scale cross-stratification can be explained by two independent hypotheses: the effect of flashy flood hydrographs on bedform preservation (flood hypothesis) or bedform preservation in the presence of larger migrating barforms (hierarchy hypothesis). We estimated bedform turnover timescales to quantitatively assess these competing hypotheses and contextualize their implications. Under the flood hypothesis, field measurements are consistent with enhanced bedform preservation driven by flashy flood hydrographs with flood durations ranging on the order of hours to a few days, which are consistent with perennial fluvial systems subject to heavy rains and tropical storms. Alternatively, under the hierarchy hypothesis, field measurements are consistent with bedform climb angles that range from 10−2 to 10−1, reflecting rapid bar migration. Our work provides a novel way of investigating fluvial discharge variability in the geologic past, and we outline the potential next steps to disentangle the relative controls of flow variability and morphodynamic hierarchy in controlling bedform preservation in ancient fluvial systems.

Manipulation of Barley Development and Flowering Time by Exogenous Application of Plant Growth Regulators.

Matching flowering time to the optimal flowering period in Mediterranean cropping zones is pivotal to maximize yield. Aside from variety selection and sowing date, growers have limited options to alter development in season. Plant hormones and growth regulators are used in perennial horticultural systems to manipulate development and floral initiation. In this study, a range of plant hormonal products were tested to analyze their effects on barley (Hordeum vulgare L) development by exogenous spray applications. Plants were grown in controlled conditions under long and short photoperiods with different vernalization treatments. The gibberellin (GA) products demonstrated the greatest potential for altering development. The GA inhibitor trinexapac-ethyl was able to delay the time to flowering in genetically divergent barley cultivars by up to 200 degree days under controlled conditions. A similar delay in flowering could be achieved via application at both early (GS13) and late (GS33) stages, with higher rates delaying flowering further. Notably, trinexapac-ethyl was able to extend the duration of pre-anthesis phases of development. By contrast, GA3 was unable to accelerate development under extreme short (8 h) or long (16 h) day lengths. There was also little evidence that GA3 could reproducibly accelerate development under intermediate 10–12 h day lengths. In addition, sprays of the cytokinin 6-benzyladenine (6-BA) were unable to reduce the vernalization requirement of the winter genotype Urambie. The present study provides baseline data for plant growth regulator treatments that delay cereal development. These treatments might be extended in field studies to align flowering of early sown crops to the optimal flowering period.

Ecological assessment of soil mite communities in diverse fodder production systems of semi–arid central India

The agrarian community of North West region of Bundelkhand in Central India is mainly dependent on livestock rearing and related activities. In order to support the livestock-based economy of the area, a number of fodder and pasture development schemes are promoted by government of India. The hypothesis is that various such systems due to change in land management and vegetation pattern; may affect soil structure and native soil biota. This study presents ecological assessment of soil mite communities in selected fodder production systems in this geographical region. Mites, the most diversified among soil biota are considered effective bio-indicators of soil conditions. So, in this study, their community structure, seasonal abundance were closely monitored and analyzed in different fodder-based land utilization schemes viz., natural grasslands, cultivated pastures (Cenchrus ciliaris + Stylosanthes hamata), pure tree stands of Albizia amara, silvipstures (tree + grass) and fodder crop cultivation. Mites were represented by 44 families under 4 suborders. Most dominant groups (families) observed were Tarsenomidae,Caligonellidae, Gamasellus,Dermanyssoidea, Scheloribetidae, Epilohmanniidae, Oppiidae, Galumnidae, Perlohmanniidae, Orobatulidae and Hydrozetidae. Peak population buildup was recorded in the month of August. Diversity was low in annual fodder cultivation system and bare land situations. Perennial fodder production systems namely, open tree stand of Albizia amara, natural grassland, improved pastures and silvipasture systems supported higher diversity of mite fauna. Greater soil mite diversity in such carefully designed perennial systems indicate that such systems might ecologically sound and would achieve long term fodder sustainability for the region.

Effect of growing degree days, day of the year, and cropping systems on reproductive development of Kernza in Kansas

AbstractReproductive growth and development of cool‐season grasses is primarily driven by air temperature and photoperiod. This study was conducted near Salina, KS, to model the effects of growing degree days (GDD), day of the year (DOY), and cropping systems on first‐ and second‐year intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] (IWG) in Kernza perennial grain production systems. In 2018 and 2019, GDD and DOY were highly correlated with reproductive growth and development (i.e., mean stage count, head meristem height, and leaf, stem, and head biomass fractions). Row spacing, fertilization, and intercropping with alfalfa (Medicago sativa L.) did not influence IWG reproductive growth and development. Across years, DOY more closely predicted reproductive stages than GDD, indicating a greater response to photoperiod than air temperature. After stem initiation, the fraction of total biomass allocated to leaves decreased, whereas stem and head biomass increased in response to GDD and DOY. At anthesis, stem biomass exceeded leaf and head biomass. Parameterizing GDD and DOY models for management in IWG dual‐purpose, Kernza grain production systems will require additional datasets from many locations and environments.

Economic outcomes for transitioning to organic forage production

AbstractResearch on the use of forages to transition cropland to organic production is limited. Our objective was to determine the cost of transitioning from conventional to organic production using perennial and annual forage systems. The study was conducted at the Middle Tennessee AgResearch and Education Center, in Spring Hill, TN. Five forage treatments were compared: tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] monoculture, bermudagrass [Cynodon dactlyon (L.) Pers.] monoculture, tall fescue and alfalfa (Medicago sativa L.) mixture, bermudagrass and alfalfa mixture, and an annual rotation of a cool‐season mixture, including winter wheat (Triticum aestivum L.) and winter pea (Pisum sativum L.), and a warm‐season mixture of sorghum–sudangrass [Sorghum bicolor (L.) Moench × S.orghum sudanese (Piper) Stapf] and cowpea [Vigna unguiculata (L.) Walp.]. Perennial forages were established in 2017 and 2018 following orchard removal and a fallow period. Regular production measurements began in 2019 when the plots achieved full organic certification status. Tall fescue had the lowest cost for the overall transition period. However, on a cost per unit of dry matter (DM) forage mass and on a cost per unit of crude protein (CP) basis, all treatments were similar, with a range between US$0.02 and $0.03 lb–1 for DM forage mass and between $0.15 and $0.20 lb–1 for CP, except for the more costly bermudagrass monoculture that was $0.06 lb–1 DM forage mass and $0.40 lb–1 CP. Given the lack of a premium during the transition period, tall fescue was the most cost‐effective transition forage.

Resilience of breadfruit agro-ecosystems in Hawaiʻi during the COVID-19 pandemic

BackgroundThe COVID-19 pandemic is interrupting domestic and global food supply chains resulting in reduced access to healthy diverse diets. Hawaiʻi has been described as a model social-ecological system and it has been suggested that indigenous agro-ecosystems have the potential to be highly productive and resilient under changing land-use and climate change disturbance. However, little research has yet been conducted exploring the disruption and resilience of agro-ecosystems in Hawaiʻi caused by the COVID-19 pandemic. The breadfruit tree (Artocarpus altilis; Moraceae) is a signature, multi-purpose-tree of the complex perennial agro-ecosystems systems in Oceania.MethodsThis case study explores the ways in which the breadfruit agro-ecosystems of Hawaiʻi have shown resilience during the COVID-19 pandemic.ResultsOur study suggests that breadfruit has increased its value as a subsistence crop during the COVID-19 pandemic, even in a developed economy like Hawaiʻi, and that resilience of Hawaiian breadfruit agroe-cosystems during a crisis can be supported through cooperatives and food-hubs.

Potencijalni rizici i problemi kod gajenja višegodišnjih energetskih useva

Second-generation biofuel production systems are significantly better than first-generation systems. However, the size of areas in which the energy crops are grown depends on public support, and it decreases if public support is missing. Despite all the environmental and economic benefits, perennial energy crops do not currently play a significant role. It is believed that available land areas will be a basic limiting factor for cultivating biofuel crops in the EU. On the other hand, there is significant untapped potential for bioenergy production in abandoned and marginal land in Southeast Europe. At the same time, perennial energy crops are investments with certain risks. Economically viable production of dedicated energy crops will be difficult to achieve on most lands classified into V-VIII land capability classes. In terms of the risk of farming investments, maize has an advantage over all perennial energy crop systems. We have identified 10 types of risks for successful production of energy crops: (1) Crop water supply; (2) Weed infestation in crops; (3) Risks of frost damages; (4) Crop lodging; (5) Crop diseases and pests; (6) Short harvest periods and variable yields; (7) Economic viability of cultivation on land areas of lower land capability class; (8) Influences of agricultural practices and agro-ecological conditions on biomass quality; (9) Storage of harvested biomass and fire hazard; and (10) economic sanctions, war, and war surroundings. Although the cultivation of perennial energy crops has a perspective, it must be systematically planned and further improved.

The temporal distribution of cyclamen mite, Phytonemus pallidus (Acari: Tarsonemidae), in strawberry and comparison of sampling methods

Abstract Cyclamen mite, Phytonemus pallidus (Banks) (Acari: Tarsonemidae), is a pest of strawberry, Fragaria × ananassa Duchesne (Rosaceae), that injures new growth, resulting in damage to leaves and fruit. The primary source of cyclamen mite in strawberry is infested planting material, and damaged plants tend to occur in small, isolated patches in perennial production systems. In the present study, we determined through repeated sampling of strawberry plants in Ontario and Saskatchewan, Canada whether relative cyclamen mite population levels were stable in commercial fields and whether overwintering and field renovation (mowing) affected populations. In Ontario, cyclamen mite counts were significantly correlated for 66% (10 of 15) of the paired comparisons from six sampling dates in more than one year, indicating a relatively stable distribution of cyclamen mite patches in strawberry fields. Winter caused high mortality (100 times fewer mites in spring than fall) and mowing caused some mortality (10 times fewer mites post- than pre-mow). We found that more cyclamen mite motiles were extracted from plant material stored in ethanol and triple-washed than were extracted using Berlese funnels, although counts from leaves were correlated between methods. No cyclamen mites were found in Saskatchewan. Knowing that cyclamen mite patches are local and spread is negligible will facilitate targeted applications of controls.

Perennial ryegrass (Lolium perenne) culm and inflorescence density in lawns: Effects of nitrogen fertilization and scalping timing and height

AbstractDuring late spring and early summer, perennial ryegrass (Lolium perenne L.) produces reproductive structures (i.e., culm and inflorescence), that decrease turf quality due to stemminess (i.e., culm remaining) after mowing. Research is required to understand the impact of management practices on visible culm and inflorescence presence. Field experiments were conducted to evaluate perennial ryegrass culm, inflorescence, and turf canopy responses due to various nitrogen (N) fertilization levels, scalping timings and heights. In Experiment 1, N fertilization rates ≥24 kg N ha−1 applied in early May with a slow‐release fertilizer prior to peak flowering (i.e., late May to early June) visibly decreased culms and inflorescences compared with 0 and 12 kg N ha−1. Higher N fertilizer levels, especially 98 kg N ha−1, also resulted in fewer necrotic culms remaining later in the summer along with greater overall turf quality and reduced weed cover. In Experiment 2, scalping perennial ryegrass at 3.8 or 5.1 cm on 25 May, the closest proximity prior to peak flowering, provided the lowest area under the curve (AUC) of green flowering culms. Scalping during or after peak flowering resulted in similar AUC values compared with nonscalped (7.6 cm) turf but did decrease the presence of necrotic culms later in summer to help improve turf quality. Overall, N fertility with a slow‐release fertilizer or a well‐timed scalping influences spring culm and inflorescence density and necrotic culm stemminess in perennial ryegrass turf systems. Additional research on physiological responses, such as carbohydrate partitioning, to these management practices is required.

Evaluation of Perennial Grass-legume Cropping Systems for Year-round Supply of Fodder for Dairy Farms

Background: Long-term and stable livestock productivity could be possible only through a year-round supply of quality green fodder and it is essential for the sustainability of dairy farms. The year-round supply of quality green fodder is challenging to livestock farmers; however, it is possible by adopting perennial grass-legume intercropping systems. Methods: A field experiment with eight treatments consisting of two perennial grasses (Napier- bajra hybrid grass and guinea grass) alone or in combination with three fodder legumes (Lucerne, Hedge Lucerne and Sesbania) was conducted for 3 years (2016-17, 2017-18 and 2018-19) in a sandy loam soil at the Agricultural Research Institute, Professor Jayashankar Telangana State Agricultural University, Hyderabad. The treatments were replicated thrice in a randomized block design. Perennial grasses were raised in paired row method (row to row 120cm and plant to plant 60 cm. The legume intercrops were grown with their respective spacing within 120 cm row. Sesbania inter crop was allowed to grow for 6 months and later trimmed to a height of 1 meter in the establishment year. Growth parameters were measured only for grasses at each harvesting and green fodder, dry matter and crude protein yields were recorded for both grasses and legumes at each cut and accumulated annually (total 6 cuts/year) for statistical analyses. Result: The results indicated that among the grasses, Napier-bajra hybrid recorded significantly higher green fodder, dry matter and crude protein yields; in case of leguminous inter crops, Sesbania recorded highest green fodder, dry matter and crude protein yields followed by Hedge Lucerne. About total productivity of the system, Napier-bajra hybrid + Sesbania (2:1) cropping system recorded highest green fodder, dry matter and crude protein yields. Highest net returns and B:C ratio was also noted with Napier bajra hybrid +Sesbania (2:1) cropping system and proved to be the best perennial fodder system for year-round supply fodder to the livestock.

Both organic and integrated pest management of apple orchards maintain soil health as compared to a semi-natural reference system

Growing concerns about the negative environmental impacts of agriculture have resulted in the increasing adoption of farming systems that try to reconcile crop production with environmental sustainability, such as organic farming. As organic farming refrains from using synthetic inputs, it heavenly relies on maintaining soil health. However, it is still poorly understood how organic management performs in terms of maintaining soil health in real commercial and heterogeneous farm settings as compared to conventional management, and especially as compared to a natural reference system. Here, we compared a set of soil health indicators among 24 commercial apple orchards that were either managed organically or conventionally using Integrated Pest Management (IPM) practices. In addition, we quantified the same indicators in 12 semi-natural grasslands as a benchmark to assess to what extent soil processes and functions have been degraded due to agricultural practices. As soil heath indicators, we quantified soil bulk density, organic matter content, organic carbon content, organic carbon stock, total nitrogen (N), potential heterotrophic respiration, potential net N mineralization, litter decomposition and litter stabilization, and we added the diversity of the herbaceous vegetation and the soil microbiome as covariates in our models. We found no differences between organic and IPM orchards, and neither of the farming systems showed evidence of impaired soil health compared to the semi-natural benchmark, with the exception of higher decomposition rates measured in both orchard types. We observed, however, high spatial variation in soil health between drive and crop rows within the orchards. Especially in the IPM orchards, crop rows showed impaired soil health compared to the adjacent drive rows, indicating that there is still opportunity to improve soil management in the IPM system. In addition, our results show that a considerable part of the variation in soil characteristics can be attributed to the study site, suggesting that both natural heterogeneity and personal management preferences by individual farmers are more important than the management system. Overall, and at least in terms of the soil variables measured in this study, our results suggest that perennial crop systems can be managed in a sustainable way, without jeopardizing soil health.

Novel Optimal Perennial Calendar Systems vs Gregorian Calendar and Their Impact on the Energy Demand and the Environment

Have you ever missed an event because you were confused about days and dates? Do you remember the date of any specific day without looking at the calendar? Is the current Gregorian Calendar efficient enough for usage, and does it facilitate our life or make it more complicated? Have you ever thought about a simpler way to calculate days and dates in a year without using a calendar? All these questions are answered in this paper, in which authors propose two contributions, (a) a new mathematical formula that calculates the number of days in any month in the Gregorian calendar for any year, including the leap years, (b) an original optimization method that creates optimal perennial calendars. Results show that there is more than one way to create a perennial calendar using the proposed optimization model, in which the number of days in each month does not change, neither the dates. Hence, all months have the same sequence of days and dates. In other meaning, Monday becomes the first day of every month, and Sunday becomes the last day. Consequently, the calendars become much easier to memorize, and it becomes simpler to predict the days and dates in any year. In addition, the proposed optimal perennial calendar system reduces the energy demand and pollution worldwide, in which it has less impact on the environment and climate change compared to the Gregorian calendar. This is due to the fact that less printed-out calendars are produced, and less time is spent on the digital calendars to check the dates and days.

Root-To-Shoot Ratios of Flood-Tolerant Perennial Grasses Depend on Harvest and Fertilization Management: Implications for Quantification of Soil Carbon Input

Quantifying soil organic carbon stocks (SOC) is a critical task in decision support related to climate and land management. Carbon inputs in soils are affected by development of belowground (BGB) and aboveground (AGB) biomass. However, uncertain fixed values of root:shoot ratios (R/S) are widely used for calculating SOC inputs in agroecosystems. In this study, we 1) assessed the effect of harvest frequency (zero, one, two, and five times annually) on the root and shoot development of the perennial grasses Phalaris arundinacea (RCG), Festuca arundinacea (TF), and Festulolium (FL); 2) determined the effect of management on the carbon and nitrogen content in AGB and BGB; and 3) assessed the implications of R/S for SOC quantification. We found the highest yields of BGB in zero-cut treatments with 59% (FL)–70% (RCG) of total biomass. AGB yield was highest in the five-cut treatments with 54% (RCG)–60% (FL), resulting in a decreasing R/S with frequent management, ranging from 1.6–2.3 (zero cut) to 0.6–0.8 (five cuts). No differences in R/S between species were observed. Total carbon yield ranged between 5.5 (FL, one cut) and 18.9 t ha−1 year−1 (FL, zero cut), with a higher carbon content in AGB (45%) than BGB (40%). We showed that the input of total organic carbon into soil was highest in the zero-cut treatments, ranging between 6.6 and 7.6 t C ha−1 year−1, although, in the context of agricultural management the two-cut treatments showed the highest potential for carbon input (3.4–5.4 t C ha−1 year−1). Our results highlighted that using default values for R/S resulted in inaccurate modeling estimations of the soil carbon input, as compared to a management-specific application of R/S. We conclude that an increasing number of annual cuts significantly lowered the R/S for all grasses. Given the critical role of BGB carbon input, our study highlights the need for comprehensive long-term experiments regarding the development of perennial grass root systems under AGB manipulation by harvest. In conclusion, we indicated the importance of using more accurate R/S for perennial grasses depending on management to avoid over- and underestimation of the carbon sink functioning of grassland ecosystems.