Effects Of Grass-Clover Silage Quality And Application Rate On Organic Potato Performance

Most organic farmers use animal manure as a source of crop nutrients. However, recent experiments have revealed that cut-and-carry fertilisers like grass-clover silage may provide a viable alternative. The objective of the current study was to investigate the performance of an organic potato crop on a sandy soil fertilised with grass-clover silages differing in C: N ratio (16, 17, 22 and 24) and nitrogen application rate (0, 57, 113 and 170 kg N ha-1). The total tuber yield was highest for the silage with a C: N ratio of 16 (44 Mg ha-1). However, the yield difference with the silage having a C: N ratio of 24 was not more than 10% (40 Mg ha-1). In terms of N application rate, there was a linear increase in yield with N rate while the share of marketable potatoes also improved with N-rate. In the non-amended control, the potato yield was 30.5 Mg/ha, whereas with 170 kg N ha-1 this was 47.5 Mg/ha. The agronomic nitrogen efficiency (ANE; kg tubers per kg applied N) was not affected by either the C: N ratio or the N application rate. However, ANE values tended to be highest for the C: N ratio of 16 (115 kg tubers/kg N) and an application rate of 170 kg N ha-1 (100 kg tubers/kg N). Overall, crop performance and N-utilisation were more than adequate which underlines that grass-clover silage can be considered as a potential substitute for animal manure sources

Interpretation of results from on-farm experiments: manure-nitrogen recovery on grassland as affected by manure quality and application technique. 1. An agronomic analysis

In a 5-year field experiment, a comparison was made between the manure application practices of two adjacent dairy farms in the north of the Netherlands. Grassland management systems at Drogeham and Harkema contrasted in manure application technique (surface application versus shallow injection, respectively), quality of applied manure (slurry + MX: slurry with Euromestmix® clay mineral additive versus regular slurry), and some relevant site characteristics (high versus low soil organic matter content and soil moisture supply). Effects of manure types and application techniques, and treatment of the soil with a micro-organism supplement, were tested in a factorial experiment at the two sites, two blocks per site, one with and one without additional application of 157 kg N ha–1 year–1 inorganic fertilizer. Apparent N recovery was higher after shallow injection than after surface application. For plots receiving no additional inorganic fertilizer, this difference was largest for slurry + MX applied at site Harkema, since this slurry–site combination resulted in the highest observed average apparent N recovery following shallow injection (47%) and the lowest N recovery following surface application (20%). For plots receiving additional inorganic fertilizer N the contrasts between treatments were less pronounced. Year effects on N uptake and dry matter production could be related to cumulative temperature and precipitation surplus over the growing season. A simple comparison between the grassland management systems was carried out based on the response curves derived from the experiment. This demonstrated that the grassland system where slurry was applied by shallow injection is not necessarily the lowest in actual amount of N not accounted for (i.e., potentially lost). The efficiency of the Harkema system strongly depended on high N recovery, but showed high potential losses in some years and a high herbage crude protein content in other years, due to the low DM production capacity. On the other hand, the Drogeham system was tuned to high DM production and was characterized by higher system stability, as reflected by more stable relationships between DM production and N not accounted for and herbage crude protein content. These differences between the systems were probably to a large extent caused by differences in water balance and soil organic matter content

Can herbage nitrogen fractionation in Lolium perenne be improved by herbage management?

peer-reviewedThe high degradability of grass protein is an important factor in the low nitrogen (N) utilization of grazing bovines in intensive European grassland systems. We tested the hypothesis that protein degradability as measured by the Cornell Net Carbohydrate and Protein System (CNCPS) protein fractionation scheme, can be manipulated by herbage management tools, with the aim to reduce N loss to the environment. A field experiment comprising the factorial combinations of three fertilizer N application rates (0, 90 and 390 kg N ha−1 year−1), three regrowth periods (2–3, 4–5, and 6–7 weeks), two perennial ryegrass (Lolium perenne L.) cultivars [Aberdart (high sugar content) and Respect (low sugar content)] and two cutting heights (approximately 8 and 12 cm) was conducted at Teagasc, Johnstown Castle Research Centre, Wexford, Ireland. The plots were sampled during four seasons [September/October 2002 (late season), April 2003 (early season), May/June 2003 (mid season) and September 2003 (late season)] and protein fractions were determined in both sheath and lamina material. The protein was highly soluble and on average 19% and 28% of total N was in the form of non-protein N, 16% and 19% in the form of buffer-soluble protein, 52% and 40% in the form of buffer-insoluble protein, and 12% and 13% in the form of potentially available cell wall N for lamina and sheath material, respectively. In both materials only 0.9% of total N was present as unavailable cell wall N. In general the herbage management tools investigated did not have much effect on protein fractionation. The effects of regrowth period, cultivar and cutting height were small and inconsistent. High N application rates significantly increased protein degradability, especially during late season. This is relevant, as it has been shown that enhanced protein degradation increases the potential N loss through urine excretion at a time when urine-N excreted onto pasture is prone to leaching. However, the effect was most evident for sheath material, which forms only a small proportion of the animals' intake. It was concluded that there appears to be little scope for manipulating the herbage-N fractionation through herbage management. The consequences for modelling herbage quality could be positive as there does not seem to be a need to model the individual N fractions; in most cases the N fractions can be expressed as a fixed proportion of total N instead

Interpretation of results from on-farm experiments: manure-nitrogen recovery on grassland as affected by manure quality and application technique. 2. A sociological analysis

This article discusses the outcomes of a re-analysis of a grassland experiment, by locating it within the wider institutional context composed of well-established routines used in agronomic research and the dominant epistemological tradition of agricultural sciences. It is argued that both, research routines and epistemological tradition, are strategic pillars of the reigning socio-technical regime. They contribute to path-dependency, thus reinforcing the uni-lateral development tendency centring on technological solutions that fit within the dominating regime. An important, albeit probably unintended consequence is that promising novelties are obscured within and through research, thus blocking a potentially highly effective road towards sustainability

Exploración de opciones agroecológicas en el sistema de milpa de la Costa Chica, México

Los sistemas de producción de la Costa Chica enfrentan serios problemas de degradación del suelo y baja productividad de maíz y jamaica. Esta situación demanda el diseño e implementación de alternativas agroecológicas para revertir esta problemática. Diversos protocolos experimentales que incluyeron opciones de fertilización e integración de leguminosas se desarrollaron en milpas de agricultores. Con base en los resultados encontrados se realizaron exploraciones a través de modelaje para evaluar el impacto de esas alternativas en el rendimiento de maíz y en el balance de materia orgánica a nivel sistema de producción. Los resultados demostraron que la integración de los componentes evaluados (fertilización, leguminosas y retención de residuos) tuvo efectos positivos en los ingresos familiares y en el balance de materia orgánica.Farming systems in Costa Chica, Mexico face problems related to soil degradation and low crop productivity. This situation requires designing and implementing agroecological alternatives to improve cropping systems. Several experimental trials that included fertilization and intercropping of legumes in current milpa systems were carried out in farmers´ fields. Based on the results modeling explorations were carried out to evaluate the impacts of these field-level agroecological options at farm level. The results showed that the integration of the evaluated components (fertilization, legumes and crop residues retention) had positive effects on family income and organic matter balances.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Infestation by Coffee White Stem Borer, Xylotrechus quadripes, in Relation to Soil and Plant Nutrient Content and Associated Quality Aspects

<p>Infestation by coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) is becoming severe in parts of Asia and Africa. In recent years, the pest has also been found in North and South America. This study in Gulmi District, Nepal, aimed to determine the severity of infestation by coffee white stem borer in relation to soil and plant nutrient content and associated quality aspects. Eighty plantations of coffee, Coffea arabica L., were inspected, 68 coffee growers were interviewed, and 120 soil and plant samples were analyzed. During the interviews, 72% respondents claimed coffee white stem borer was a major hurdle to production of coffee. Depending on the amount of damage, annual yield loss in infested plantations was as much as 60%. Based on principal component analysis (PCA), plants growing with more soil nitrogen, pH, and organic matter were healthier than plants with less. Results suggested that soil attributes are crucial for management of coffee white stem borer.</p

Growing Coffee in the Shade : A Strategy to Minimize the Prevalence of Coffee White Stem Borer, Xylotrechus quadripes

Coffee white stem borer, Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) is a major coffee pest in parts of Asia and Africa. In recent years, the pest has also been found in American countries. This study in Gulmi District, Nepal, aimed to determine the infestation by coffee white stem borer in relation to coffee plantations in shade or sun. Eighty plantations of coffee were inspected and 68 coffee growers were interviewed. Of 68, 52 (76%) respondents reported high to very high infestation by pests in sun coffee, while 50 (74%) claimed low to very low infestation in shade coffee. There was a significant (χ2 = 5.8, p 2 = 75, p < 0.05) greater for sun (60%) compared to shade (40%) coffee plants. The total number of infested plants showed significant negative correlation (r =-0.54, n = 68, p < 0.05) with the number of permanent shading trees in plantations. Results suggested that developing a stand of permanent shading trees could be a potential strategy for management of coffee white stem borer.</p

Influence of reduced tillage and fertilisation regime on soil quality indicators in an organic potato production system

The aim of this study was to assess the short-term effects of tillage practice (reduced tillage – RT; standard tillage – ST) and fertilisation regime (solid cattle manure – SCM; lucerne pellets – LP; grass/clover silage – GCS) on soil quality indicators in an organic potato (Solanum tuberosum L.) production system. Use of RT enhanced the biomass and number of earthworms compared with ST. Concentrations of soil mineral N ((Formula presented.) and (Formula presented.)) showed similar decreasing patterns over time across both tillage systems during the potato production period. However, soil mineral N was overall higher in the 0–15 cm soil layer for RT and in the 15–30 cm layer for ST. Soil bulk density was higher for RT than ST at 1, 4 and 7 weeks after planting, while a linear reverse correlation was found between soil bulk density and tuber yield. Although both soil temperature and soil moisture content were not found to be greatly affected by tillage practice, net soil N mineralisation was estimated to be 65 kg N ha−1 greater under ST than RT for the potato production period. The application of LP and GCS resulted in higher mid- and end-season soil mineral N concentrations and crop N accumulation at harvest compared to SCM. During initial adaptation to reduced tillage practices in organic potato systems, farmers need to carefully weigh potential conflicts between initial yield reductions and soil conservation goals

Influence of reduced tillage and fertilization regime on crop performance and nitrogen utilization of organic potato

The majority of Dutch farmers perceive that mouldboard ploughing prior to potato planting is necessary, despite its negative impacts on inherent soil fertility and soil structure. An innovative agronomic practice in Dutch organic agriculture is the use of cut-and-carry fertilizers with which above-ground biomass of crops with high nitrogen content (e.g. grass/clover) is harvested and transferred to other fields as plant-based fertilizers. The objective of this study was to investigate the interactive effects of two tillage systems (reduced tillage (RT), standard tillage (ST)) and three organic fertilizer amendments (solid cattle manure (SCM), lucerne pellets (LP), grass/clover silage (GCS)) on crop performance and nitrogen utilization of organic potato. Use of RT decreased tuber yield by 13.4 % compared to ST due to lower average tuber size which was related to higher soil bulk density and increased vulnerability to drought stress during tuber bulking. On the other hand, use of RT positively affected nitrogen utilization and tuber quality in terms of specific gravity, dry matter and starch contents. However, the price premium associated with enhanced tuber quality may not offset the observed yield gap between RT and ST. Plant-based fertilizers enhanced nitrogen utilization in terms of apparent nitrogen recovery compared to animal-based. Although use of LP resulted in the highest yield for both tillage systems, its high price may be cost-inhibitive. An integrated approach taking into account N release patterns, environmental conditions, final yields, and production costs is needed in order to optimize resource use efficiency and overall profitability for farmers.ISSN:1879-4238ISSN:1879-424