Agriculture, Volume 7, Issue 3 (March 2017) – 15 articles

A field experiment was conducted for two years in the Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center, Iruma, Saitama, Japan from March 2014 to December 2015. Controlled release fertilizers (CRF) or organic fertilizers (ORG), which are a mixture of chicken manure and oil cake, were applied with the amount of 450 kg·N·ha⁻¹·year⁻¹ in 2014 and 397 kg·N·ha⁻¹·year⁻¹ in 2015. Nitrous oxide (N₂O) emissions from soil in green tea fields were measured by the closed chamber method. The results showed that CRF has significantly lower N₂O compared to ORG. The cumulative N₂O emissions from CRF accounted for 51% of N₂O emissions from ORG fields and 138% of control with no fertilizer treatment. The N₂O flux from the row was higher than that under the canopy, since fertilizer was applied on the row. However, the total emission from the area between the rows was lower than that under the canopy because the area ratio between the row and canopy was 1:5. Full article

Intensive agricultural practices in farming systems in eastern Australia have been identified as a contributor to the poor runoff water quality entering the Great Barrier Reef (GBR). A field investigation was carried out to measure the off-farm water quality and productivity in a coastal farming system in northeastern Australia. Two vegetable crops (capsicum and zucchini) were grown in summer 2010–2011 and winter 2011 respectively using four different management practices (Conventional—plastic mulch, bare inter-row conventional tillage and commercial fertilizer inputs; Improved—improved practice with plastic mulch, inter-row vegetative mulch, zonal tillage and reduced fertilizer rates; Trash mulch—improved practice with cane-trash or forage-sorghum mulch with reduced fertilizer rates, minimum or zero tillage; and Vegetable only—improved practice with Rhodes grass or forage-sorghum mulch, minimum or zero tillage, reduced fertilizer rates). Results suggest improved and trash mulch systems reduced sediment and nutrient loads by at least 50% compared to conventional systems. The residual nitrate nitrogen in soil accumulated at the end-of-break crop cycle was lost by deep drainage before the subsequent sugarcane crop could utilize it. These results suggest that future research into establishing the linkages between deep drainage, groundwater quality and lateral movement into adjacent streams is needed. The improvement in runoff water quality was accompanied by yield reductions of up to 55% in capsicum and 57% in zucchini under trash mulch systems, suggesting a commercially unacceptable trade-off between water quality and productivity for a practice change. The current study has shown that variations around improved practice (modified nutrient application strategies under plastic mulch, but with an inter-space mulch to minimize runoff and sediment loss) may be the most practical solution to improve water quality and maintain productivity. However, more work is required to optimize this approach and thus reduce the size of any potential productivity and profitability gap that would necessitate an expensive policy intervention to implement. Full article

The citrus by-products pectin and polyphenols were obtained from Citrus x lantifolia residues. The use of acid type, solute-solvent ratio, temperature, and extraction time on pectin yield recovery was evaluated using a factorial design 3⁴; pectin physicochemical characterization, polyphenol profile, and antioxidant activity were also determined. Results indicated a total polyphenol content of 3.92 ± 0.06 mg Galic Acid Equivalents (GAE)/g of citrus waste flour in dry basis (DB), with antioxidant activity of 74%. The presence of neohesperidin (0.96 ± 0.09 mg/g of citrus flour DB), hesperidin (0.27 ± 0.0 mg/g of citrus flour DB), and ellagic acid (0.18 ± 0.03 mg/g of citrus flour DB) as major polyphenols was observed. All of the factors evaluated in pectin recovery presented significant effects (p < 0.05), nevertheless the acid type and solute-solvent ratio showed the greatest effect. The highest yield of pectin recovery (36%) was obtained at 90 °C for 90 min, at a ratio of 1:80 (w/v) using citric acid. The evaluation of pectin used as a food ingredient in cookies elaboration, resulted in a reduction of 10% of fat material without significant texture differences (p < 0.05). The pectin extraction conditions and characterization from these residues allowed us to determine the future applications of these materials for use in several commercial applications. Full article

Nitrate loss from bioenergy crop fields has attracted considerable attention during the last few years because of its potential negative impact on aquatic and human health. Both controllable and uncontrollable factors for nitrate loss have been the subject of several previous studies. Due to differences in climate, biophysical dissimilarities and land management characteristics in different parts of the world the factors affecting nitrate loss are often inconsistent and hence difficult to generalize. Therefore, reanalyzing the experimental field or plot scale studies to understand the nitrate loss factors in crop fields is useful and necessary in developing management strategies for reducing nitrate loss. This research synthesized and investigated 36 peer reviewed scientific journal articles related to selected bioenergy crop fields that included: continuous corn, corn in rotation with soybean, switchgrass and Miscanthus to conduct a meta-analysis of the available research. In this study, factors such as drain tile spacing, tillage practices, type and timing of the fertilization rate, irrigation and various other factors, which are challenging to represent in regression equations, were also systematically analyzed. In addition, various other agronomic characteristics that are attributed too nitrate loss are caused by perennially planted bio energized crops such as Miscanthus and switchgrass. Results indicated that 49% of nitrate loss through surface runoff from corn fields is directly related to the annual precipitation and fertilization rate. Multiple linear regression equations were developed to estimate the annual subsurface nitrate loss for the continuous corn fields with a R² value of 0.65, 0.58 and 0.26 for sandy loam, silty loam and clay loam, respectively. Our analysis resulted in the conclusion that corn has a 2 to 3 times higher nitrate loss in surface runoff compared to switchgrass. Likewise, continuous corn and corn in rotation with soybean contributed more than 9 times the subsurface loss of nitrate compared to the established subsurface loss attributed to the Miscanthus and switchgrass. Full article

Ethnobotanical investigations on local oilseed species in Burkina Faso revealed that oils from tree oilseeds are frequently used for food, cosmetics and traditional medicine by local people. To test the bio-preservative capacity, the effect of the oilseed extracts on the stabilization of Shea butter was evaluated. Levels of bioactive phyto-components were evaluated through several methods. Some aspects of the quality of oilcakes were evaluated based on their inhibitory capacity on the endogenous digestive enzymes of cattle. For fat stabilizing quality, the extract from Lannea microcarpa Engl. & K. Krause has showed the largest increase (91.47%) in the Rancimat induction time (TIR) of Shea butter. Using DPPH and FRAP methods for prevention or scavenging of free radicals, the results evidenced the highest activity with extracts of L. microcarpa. With respect to the feed quality of the oilcakes, the IC₅₀ obtained with α-amylase and trypsin have showed that the ethanolic extracts of Pentadesma butyracea Sabine (1824) is less toxic for cattle. These results suggest that phenolic compounds extracted from these native oilseeds, especially those of Lannea microcarpa, can be used as biological antioxidants for bio-preservation of edible fats. In addition, the by-products of the oil-extraction can be valorized as nontoxic and protein-rich oilcakes for livestock feed. Full article

This paper probes effects of the evolvement of labor resources on technical efficiency in crop production in rural China. Based on twelve years of data on crop production of 30 provinces in China, a stochastic frontier production function model is used to measure crop production efficiency in three crop-functional areas—the production area, the consumption area, and the balanced area. Then effects of both quantity and quality change in labor force on technical efficiency in different regions of China are analyzed. Results show that rural China generally has an increasing number of employees shifted to non-agricultural sectors and a decreasing trend of the stock of human capital. However, both these two changes in rural labor force have significantly positive effects on improving crop production efficiency. In addition, China’s technical inefficiency is at an average of 22.2%. Dynamically, the technical efficiencies show a tendency to rise steadily throughout China and in three areas, while the consumption area possesses the highest technical efficiency. Those results may lend some experience for other countries that are currently experiencing rural labor force and economic transition. Full article

Successional agroforestry systems (SAFS) mimic the structure of natural forests while providing economical outputs. This study clarifies how carbon cycling and carbon sequestration change during successional development of SAFS. In Brazil, three successional stages of SAFS, 6, 12, and 34 years old, were compared in terms of carbon balance. Aboveground biomass, fruit harvest, litterfall, soil respiration, and soil organic carbon were measured for two years and analyzed. Carbon sequestration expressed by net primary productivity increased with age of SAFS from 9.8 Mg·C·ha⁻¹·year⁻¹ in 6-year-old system to 13.5 Mg·C·ha⁻¹·year⁻¹ in 34-year-old system. Accumulation of plant biomass and increased internal carbon cycling in SAFS led to an intensive sequestration of carbon. SAFS can be a sustainable way of agricultural production on vulnerable tropical soils. Full article

Chickpea (Cicer arietinum L.) contributes 18% of the global production of grain legume and serves as an important source of dietary protein. An important decrease in cropping area and production has been recorded during the last two decades. Several biotic and abiotic constraints underlie this decrease. Despite the efforts deployed in breeding and selection of several chickpea varieties with high yield potential that are tolerant to diseases, the situation has remained the same for the last decade. Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris (Foc) is the major soilborne fungus affecting chickpeas globally. Fusarium wilt epidemics can devastate crops and cause up to 100% loss in highly infested fields and under favorable conditions. To date, eight pathogenic races of Foc (races 0, 1A, 1B/C, 2, 3, 4, 5 and 6) have been reported worldwide. The development of resistant cultivars is the most effective method to manage this disease and to contribute to stabilizing chickpea yields. Development of resistant varieties to fusarium wilt in different breeding programs is mainly based on conventional selection. This method is time‐consuming and depends on inoculum load and specific environmental factors that influence disease development. The use of molecular tools offers great potential for chickpea improvement, specifically by identifying molecular markers closely linked to genes/QTLs controlling fusarium wilt. Full article

Golden Apple Snail (GAS) is the most destructive invasive rice pest in Southeast Asia. The cost of synthetic molluscicides, their toxicity to non-target organisms, and their persistence in the environment have propelled the research of plant-derived molluscicides. Most research efforts have focused on individual plant extracts for their molluscicidal potency against GAS and have not been proven to be entirely effective in rice field conditions. Selective combination of synergistically acting molluscicidal compounds from various plant extracts might be an effective alternative. In this direction, ethanolic extracts from six different plants (Neem, Tobacco, Nerium, Pongamia, Zinger, and Piper) were evaluated against Pomacea maculata Perry. Of the various combinations studied, a binary extract (1:1) of nerium and tobacco (LC₉₀ 177.71 mg/L, 48 h), and two tri-herbal extract formulations (1:1:1) of (nerium + tobacco + piper) and (nerium + tobacco + neem) were found to be most effective, with LC₉₀ values of 180.35 mg/L and 191.52 mg/L, respectively, in laboratory conditions. The synergistic effect of combined herbal extracts resulted in significant reduction in LC₉₀ values of the individual extracts. The findings of this study demonstrate that the selective combinations of potent molluscicidal herbal extracts are effective for management of P. maculata under laboratory conditions. Full article

To elucidate the effects of rice straw removal and rice straw‐based bio‐ethanol production residue application on rice growth and methane (CH4) emission from a paddy field, a lysimeter experiment with three treatments (application of rice straw after harvesting (the rice‐straw plot); removal of rice straw and the application of bio‐ethanol production residue (the Et‐residue plot); removal of rice straw (the no‐application plot)) was conducted over three years. Though the grain yields in the Et‐residue and no‐application plots tended to be slightly higher than that in the ricestraw plot, there were no significant differences among the plots (530–546 g∙m−2). Suppression of CH4 emission by the treatments was found clearly in the early part of the growing season. The total CH4 emissions during the rice‐growing season (unit: g∙C∙m−2∙period−1) followed the order of the noapplication plot (11.9) < the Et‐residue plot (14.6) < the rice‐straw plot (25.4), and a significant difference was found between the no‐application and rice‐straw plots. Consequently, bio‐ethanol production from rice straw and a following application of its residue to paddy fields is considered to be a promising technology which can obtain new sustainable energy and suppress CH4 emission without any inhibition on rice growth. Full article

Rainfed agriculture has become highly vulnerable to the depleting water resources in most arid and semi‐arid tropics (ASATs) under the effect of climate change. The impact has certainly been very high in Muooni catchment where more than 99% of the natural forest has been cleared. The warming micro‐climate is accelerated by extended deforestation, unsustainable irrigation, and water over‐abstraction in the catchment by eucalyptus and other exotic trees. The dwindling crop yields add to the farmer’s suffering. Farming communities have created various innovative ways of coping with a warming environment to increase their agriculture resiliency. These include, among others, rain water management, reforestation and agro‐forestry. To what extent have these practices been disturbed by the increasing temperatures, and decreasing rainfalls and river discharges in Muooni catchment? This study used statistical forecast techniques to unveil the past, current and future variations of the micro‐climate in Muooni catchment, and relevant factors determining farmers’ vulnerability to drought. Muooni catchment is warming by 0.8 to 1.2 °C in a century as a result of a changing micro‐climate. These changes are mainly driven by deforestation due to the high urbanization rate and agricultural practices in Muooni catchment. Centennial rainfall is subsequently plummeting at 30 to 50 mm while discharges are decreasing from 0.01 to 0.05 m3∙s−1, with unmet water demands of 30% to 95% and above. In view of the current trends of the population growth and urbanization in Muooni, agricultural expansion is seriously threatened if no appropriate policy, extension service and science based emergency measures are put in place by the Government of Kenya. Full article

There is interest in reducing or even eliminating tillage in organic production systems. In this special Issue, research teams in Europe and North America summarize recent and on-going efforts to develop conservation-tillage systems that can be used on commercial organic farms. While progress is being made in the development of organic no-tillage (no-till) systems, considerable work still needs to be done before there will be wide-spread adoption by organic farmers. Full article

Field trials were conducted on tomato for yield and quality of fruits using different types of organic and inorganic fertilizers at the horticulture farm of Bangladesh Agricultural University (BAU), Mymensingh. Fertilizer treatments were tested on two varieties of tomato ca. Roma VF and BARI 15. The fertilization treatments were T1, vermicompost (12 t/ha); T2, compost (10 t/ha); T3, integrated plant nutrient system (IPNS) or mixed fertilizers (organic 2/3 part and inorganic 1/3 part); T4, inorganic fertilizers; and a control (T5). Results showed growth and yield (20.8 t/ha) in tomato were higher in the IPNS treatment. A higher number of fruits per plant (73.7) and plant height (73.5 cm) were obtained from mixed fertilizers (organic 2/3 + inorganic 1/3) or IPNS (integrated plant nutrient system) in Roma VF than other treatments. Fruit yield and diameter were found statistically significant. No significant difference was observed in the quality (total soluble solids) of tomato fruits in both varieties’ response to the treatments. The electrical conductivity and pH of the soil were improved by the application of organic manure. Full article

The objective of this study was to conduct a systematic review of published literature on ammonia (NH₃) and enteric methane (CH₄) emissions from beef and dairy cattle operations to obtain statistically representative emission factors based on dietary intakes of nutrients or energy, and to identify major causes of emission variations. NH₃ emissions from lagoon or other manure storage facilities were not included in this review. The NH₃ and CH₄ emission rates, expressed as a percentage losses of dietary nutrients or energy, demonstrated much less variation compared with emission rates expressed in g/animal/day. Air temperature and dietary crude protein (CP) content were identified as two major factors that can affect NH₃ emission rates in addition to farm type. Feed digestibility and energy intake were identified as two major factors that can affect CH₄ emission rates expressed as a percentage losses of dietary energy. Generally, increasing productivity and feed efficiency represented the greatest opportunity for mitigating NH₃ or CH₄ emissions per unit of livestock product. Expressing CH₄ loss on a digestible energy basis rather than a gross energy intake basis can better represent the large variation among diets and the effects of varying dietary emission mitigation strategies. Full article