Discrete Event Simulation of Switchgrass Harvest Schedules

Growth characteristics of Rayong 3, a recommended cultivar with sparse branching habit, were compared with those of Rayong 1, a traditional cultivar with tall and erect stems. Root production was largely influenced by the total dry matter production during the rainy season which was closely associated with a leaf area index (LAI). Rayong 3 showed some advantages in root production when compared with Rayong 1; i) high dry matter production during the rainy season, which was associated with a high LAI due to mainly the high leaf production rate per plant, ii) a high harvest index and iii) high dry matter and starch contents of storage roots. A moderate branching habit, represented by Rayong 3, could maintain a high harvest index when the total dry matter production and leaf area incrcased under the prevailing growth conditions of cassava in Thailand.

The effects of low air humidity and low root temperature (LRT) on water uptake, growth and aquaporin gene expression were investigated in rice plants. The daily transpiration of the plants grown at low humidity was 1.5- to 2-fold higher than that at high humidity. LRT at 13°C reduced transpiration, and the extent was larger at lower humidity. LRT also reduced total dry matter production and leaf area expansion, and the extent was again larger at lower humidity. These observations suggest that the suppression of plant growth by LRT is associated with water stress due to decreased water uptake ability of the root. On the other hand, the net assimilation rate was not affected by low humidity and LRT, and water use efficiency was larger for LRT. We found that low humidity induced coordinated up-regulation of many PIP and TIP aquaporin genes in both the leaves and the roots. Expression levels of two root-specific aquaporin genes, OsPIP2;4 and OsPIP2;5, were increased significantly after 6 and 13 d of LRT exposure. Taken together, we discuss the possibility that aquaporins are part of an integrated response of this crop to low air humidity and LRT.

Growth and development of seven Oriental tobacco cultivars, representing aromatic, neutral and taste type tobacco grown in Greece, were studied at Drama, Greece, during 1982 and 1983. The growing period from transplanting to flowering ranged from 65 to 80 days and was the same for both years. plant height increase followed a sigmoid curve, the number of harvestable leaves developed almost linearly with time, and total dry weight production and leaf area increase can be described by a logarithmic curve. The effect of year on all parameters was significant, but cultivar differences were consistent. Assimilation rates during the whole period ranged from 0.1 g to 3.0 g per day per plant in 1982, and from 0.1 g to 2.7 g in 1983. Dry weight distribution in the plant parts and final yield production for the cultivars tested were also recorded.

Abstract. Corn stover is an abundant biomass, yielding typically more than 8 t dry matter (DM) ha -1 in eastern Canada at the time of grain harvest. It is usually left behind in the field because of wet conditions in the fall, its protective role against erosion and its contribution to organic matter in the soil. However, part of this biomass could be harvested in a dry form in the spring for useful applications such as animal bedding, a solid biofuel or a biomaterial feedstock. In 2009, 2010, and 2011, spring harvest of corn stover was studied in southern QuA©bec. Machinery management data were collected to evaluate the cost of four harvest scenarios. In the first scenario, stover was mowed, raked and baled using a 2.4-m disc mower, a parallel-bar rake, and a large square baler (LSB). In the other three scenarios, stover was mowed, shredded and windrowed simultaneously with a 4.6-m flail-shredder-windrower and harvested either with a large square baler, a large round baler (RB) or a self-loading wagon (SLW). Assuming a harvest period of 2.5 weeks in the spring, the largest amount of stover that could be harvested (687 t DM over 177 ha) was obtained with the SLW. Amounts of 466 to 476 t DM over 131 to 125 ha could be harvested with the round baler and the large square baler, respectively. When bales were sold outside the farm, a fertilizer value of $21.01 t -1 DM was accounted for the removal of P and K contained in the stover. The cost of harvest operations was estimated as $34.30 t -1 DM for scenario 1 (mower, rake, and LSB). It was $32.76, $29.04 and $29.67 t -1 DM for combinations of the flail-shredder-windrower and LSB, RB, and SLW, respectively. Storage costs per t DM in a shed varied considerably because of differences in bulk density: $29.87 for the LSB, $59.44 for RB and $71.85 for SLW. Results should allow effective planning of cost and operations related to dry corn stover harvested in the spring.

Use of inoculant-based technologies in legume production has been practiced for over a century but in Africa, the technology is relatively new and especially to smallholder farmers. The introduction of these technologies has enabled increased legume productivity as well as increased soil fertility in other countries. The inoculant-based technologies have been disseminated in Western Kenya by various organizations and projects including: Sustainable Intensification of Maize-Legume cropping systems for food security in Eastern and Southern Africa (SIMLESA) project through the Kenya Agricultural and Livestock Research Organization (KALRO)-Kakamega and Embu, Nitrogen 2 Africa (N2AFRICA), United States Department of Agriculture- National Institute of Food and Agriculture (USDA-NIFA), and Non-governmental organizations such as Appropriate Rural Development Agriculture Program (ARDAP). The dissemination targeted several counties including Bungoma, Busia and Kakamega. While past studies have assessed the adoption of inoculant technology as a single package, the effect of different inoculant- based technologies on bean yield remains unknown. There is also lack of information on the role inoculant-based technologies on bean output market participation. This study examined the use and effect of inoculant-based technologies on smallholder field bean farm households in western Kenya. A multivariate probit (MVP) model was applied to assess factors affecting farmers‟ decision on use of alternative inoculant-based technologies. In v addition, a Tobit regression was estimated to assess the effect of the use of inoculant-based technologies on household output commercialization, measured by the share of sales, among project participating households and non-participating households. Data was collected from 248 farmers stratified by participation in projects that promote inoculant-based technologies. The information was collected in August and September 2014 and included farm and farmer characteristics; household endowment with physical, financial, social and human capital; market participation and institutional factors; field bean production and input usage; and farmer knowledge/awareness and information sources. Descriptive results indicate that years of experience, total value of non-land assets and distance to the road significantly and positively affected adoption at 1percent, 5percent and 10percent error level respectively. Out of the five inoculant-based technologies demonstrated to farmers, only three were found to be widely adopted. These are: inoculant only, inoculant and farm yard manure and inoculant and fertilizer. Results from the multivariate probit regression analysis showed that the distance to agricultural extension office, group membership, project participation, wealth (proxied by the total value of non-land assets), age and gender significantly affected the use of the inoculant-based technologies. The Tobit regression analysis results showed that transaction costs (proxied by the distance to group office and group and project participation), age, years of schooling, totals assets, access to information (proxied by extension visits) and total bean production area significantly influenced the commercialization of beans by the small holder farmers.

Atypical scab symptoms were reported for the first time at the end of July in 2012 in Northern Italy (Cesena province, Emilia Romagna region) on fruit apple cultivar CIVG198 Modi® carrying the Rvi6 (=Vf) major resistance gene to Venturia inaequalis; it is a hybrid of ‘Gala’ x ‘Liberty’ with more than half the total world production area of cv ‘Modi’ located in Italy. The symptoms were also established in all the following years and Venturia asperata was identified as a causal agent of these atypical scab symptoms through morphological studies and molecular analysis of conidia from fruits and ascospores from overwintered leaves, using specific primers for V. asperata, V. inaequalis and V. pirina. Pathogenicity tests carried out on fruit at different phenological stages showed only light symptoms. Venturia asperata could represent an emergent disease for cv ‘Modi’ and disease control may be necessary.

The negative effects of elevated concentrations of inorganic aluminium on aquatic organisms are well documented. Acid deposition is often cited as a main driver behind the mobilisation and speciation of aluminium in soils and surface waters. In the study, we tested the hypothesis that sulphur deposition is the main driver for elevated concentrations of inorganic aluminium in 114 base poor, boreal Swedish streams. However, the deposition of anthropogenic sulphate has decreased substantially since it peaked in the 1970s, and at the current deposition levels, we hypothesise that local site parameters play an important role in determining vulnerability to elevated concentrations of inorganic aluminium in boreal stream waters. Presented here are the results of a principal components analysis of stream water chemistry, acid deposition data and local site variables, including forest composition and stem volume. It is shown that the concentrations of both organic and inorganic aluminium are not explained by either historical or current acid deposition, but are instead explained by a combination of local site characteristics. Sites with elevated concentrations of inorganic aluminium were characterised by small catchments (<500 ha) dominated by mature stands of Norway spruce with high stem volume. Using data from the Swedish National Forest Inventory the area of productive forest land in Sweden with a higher vulnerability for elevated inorganic aluminium concentrations in forests streams is approximately 1.5 million hectares or 7% of the total productive forest area; this is higher in the south of Sweden (10%) and lower in the north (2%). A better understanding of the effects of natural processes and forest management in controlling aquatic inorganic aluminium concentrations is therefore important in future discussions about measures against surface water acidification.

Lowbush blueberry (Vaccinium angustifolium Ait.) production has the highest export value among all fruit crops in Canada. As blueberry flowers require insect pollination, blueberry farms rely on commercial pollinators to ensure productivity of their fields. Our study aimed to assess the impact of commercial pollinator density and diversity on lowbush blueberry yield using historical data, from 2015 to 2021, across various production contexts. The analysis included 178 blueberry fields, representing approximately 3,000 ha and 11% of Québec's total crop production area. Data on field size, berry yield, commercial pollinator density/diversity (honey bees; Apis mellifera L. [Hymenoptera: Apidae]), bumble bees; Bombus impatiens Cresson [Hymenoptera: Apidae], and alfalfa leafcutter bees; Megachile rotundata Fabr. [Hymenoptera: Megachilidae]), establishment year, and management system were collected for each field. Additionally, we examined data on honey bee hive strength, landscape structure, and meteorological factors influencing yield. Results showed significant yield increase at certain densities of honey bee hives and frames, bumble bee hives and alfalfa leafcutter bee gallons. The diversity of commercial pollinators used in the fields also increased crop yield. Other key factors influencing lowbush blueberry yield included the year, snow cover during winter, field age, and frost events during pollination. This study clarifies the relationship between commercial pollinators and lowbush blueberry productivity while accounting for several other agroeconomic variables, and demonstrates that increasing managed pollinator density and diversity lead to higher yields for lowbush blueberry growers.

Modeling harvest and biomass removal effects on the forest carbon balance of the Midwest, USA

Global situation for organic tree fruits

High yielding varieties of cereal crops were the major contributors to India's Green Revolution in 1960s and till date these varieties have been largely contributing to India's bread basket. Uttarakhand is primarily an agricultural state although its share in the country's total area and production is negligible. In this paper the authors have attempted to measure the technical and economic efficiencies of improved varieties of paddy and wheat in lower Shivalik hills of Uttarakhand during 2017-20. Uttarakhand is primarily an agricultural state although its share in the country's total area and production is negligible. Economic efficiencies of the varieties were measured by benefit-cost ratio (BCR) andnet return (NR). Technical efficiencies were measured by Box plot technique in R software. Kernal density plot was used to represent yield variation among the varieties. The findings revealed that PB 1121 paddy and HD 2967 wheat respectively were the best varieties in terms of technical efficiency (productivity) and economic efficiency (BCR andNet Return). Estimates of t-test also show the significant differences in BCR and net return between improved and local varieties. Thus, study shows that the positive impacts of improved varieties of the major crops have significantly contributed to productivity, farm income and livelihood in the lower Shivalik hills of Uttarakhand which, in turn, mayprovide prospective implications towards country's total production and food security.

The main purpose of this study was to forecast Nigeria total cashew nut area production and total crop harvested. Forecasting future land that may be used under cultivation will help Nigeria Government to make policies on available land use and further cash crop production capacity. Projection of total cash crop production is important for implementing proper measures to increase earnings from exports in the country. The study was conducted to forecasts total area and production for Cashew in Nigeria. The findings of the study are based on data from the years (1961 to 2020) and was taken from the database of FAO (2022). ARIMA Models from time series analysis were applied. In the model selection criteria, the model with the lowest Akaike coefficients, SBIC, AIC, sum of squared residual and Mean Absolute Percentage Errors (MAPEs) of forecasting values were used in selecting an adequate model. Thus, ARIMA 1,1,0 was selected for both the harvested area and total production. Forecasting of the data was done up to 2040. The forecasted values were area harvested (190,779.74ha) and production (129,541.18 metric tonnes). The study presents an insight to national policy makers regarding this essential crop and provides them with a reference range of values in area harvested and production in future so that they may be able to effectively deal with cashew production in Nigeria.

Large-scale biofuels production: A possible threat to soil conservation and environmental services

Can crop simulation models be used to predict local to regional maize yields and total production in the U.S. Corn Belt?

In the bioenergy industry, highway hauling cost is typically 30%, or more, of the average cost of feedstock delivered to a biorefinery. Thus, truck productivity, in terms of Mg/d/truck, is a key issue in the design of a logistics system. One possible solution to this problem that is being explored is the utilization of modular pellet depots. In such a logistics system, raw biomass (i.e., low-bulk-density product) is converted into pellets (i.e., high-bulk-density product) by several smaller-scale modular pellet depots instead of by a single larger-capacity pellet depot. A truckload of raw biomass (e.g., round bales) is 16 Mg and a load of pellets is 34 Mg. The distribution of depots across a feedstock production area can potentially have an impact on the total truck operating hours (i.e., raw biomass hauling to a depot + pellet hauling from the depot to the biorefinery) required to deliver feedstock for annual operation of a biorefinery. This study examined three different distributions of depots across five feedstock production areas. The numbers of depots were one, two, and four per production area for totals of five, ten, and twenty depots. Increasing the number of depots from five to ten reduced raw biomass hauling hours by 12%, and increasing from five to twenty reduced these hours by 30%. Total hauling hours (raw biomass + pellets) were reduced by less than 1% with an increase from five to ten and by about 11% with an increase from five to twenty. The modular pellet depot concept demonstrated potential for providing improvements to biorefinery logistics systems, but more research is needed to optimize this balance.