Forage Cropping Systems Research Articles

Dissolved Organic Carbon in Runoff and Tile‐Drain Water under Corn and Forage Fertilized with Hog Manure

Dissolved organic carbon (DOC) export from soils can play a significant role in soil C cycling and in nutrient and pollutant transport. However, information about DOC losses from agricultural soils as influenced by management practices is scarce. We compared the effects of mineral fertilizer (MF) and liquid hog manure (LHM) applications on the concentration and molecular size of DOC released in runoff and tile-drain water under corn (Zea mays L.) and forage cropping systems. Runoff and tile-drain water samples were collected during a 2-mo period (October to December 1998) and DOC concentration was measured. Characterization of DOC was performed by tangential ultrafiltration with nominal cut-offs at 3 and 100 kDa. Mean concentration of DOC in runoff water (12.7 mg DOC L(-1)) was higher than in tile-drain water (6.5 mg DOC L(-1)). Incorporation of corn residues increased the DOC concentration by 6- to 17-fold in surface runoff, but this effect was short-lived. In runoff water, the relative size of the DOC molecules increased when corn residues and LHM were applied probably due to partial microbial breakdown of these organic materials and to a faster decomposition or preferential adsorption of the small molecules. The DOC concentration in tile-drain water was slightly higher under forage (7.5 mg DOC L(-1)) than under corn (5.4 mg DOC L(-1)) even though the application rates of LHM were higher in corn plots. We suggest that preferential flow facilitated the migration of DOC to tile drains in forage plots. In conclusion, incorporation of corn residues and LHM increased the concentration of DOC and the relative size of the molecules in surface runoff water, whereas DOC in tile-drain water was mostly influenced by the cropping system with relatively more DOC and larger molecules under forage than corn.

Annual Variation in Herbage Dry Matter Yield under Some Forage Cropping Systems on the Heavy Soil in Southern Kyushu

Annual Variation in Herbage Dry Matter Yield under Some Forage Cropping Systems on the Heavy Soil in Southern Kyushu

Input-output cost of agronomic production of crops under rotate growing condition for applying to Mediterranean Italian buffaloes

Forage availability with low cost of production is the main farmer requisite for obtaining a competitive husbandry dairy product in the market. Cropping system for silage consumption differently impact the cost of Milk Feeding Unit (MFU) and sustainable agronomic cultivation of herbage production. The experiment aimed to assess the analytical cost of MFU per hectare in four forage cropping system models based on two crops per year bred under irrigated and rainfed condition in a Mediterranean site with intensive buffaloes breeding pressure.

Forage Cropping System of Natural-Reseeded Barnyardgrass (Echinochloa crus-galli) for Abandoned Paddy Fields and Its Feasibility in Mountainous Area

A field experiment was carried out from October 1999 to September 2001 to establish a cropping system with Italian ryegrass (Lolium mulliflorum) and natural-reseeded barnyardgrass (Echinochloa crus-galli) in an abandonedpaddy field. Ryegrass was sown in October 1999 and 2000, and barnyardgrass was sown only in October 1999. A split-split plot arrangement was applied with the ryegrass varieties (an early-maturing type (EM) and a mid- to late-maturing type (LM)) as the main plot factors. The subplot factor was barnyardgrass at various sowing rates (100, 200, and 300 g/a). EM and LM were harvested twice and once, respectively, the following spring, and barnyardgrass was harvested twice: once in the summer and once in the autumn in both the EM and LM plots. In both years, the ryegrass yields depended significantly on the variety: the yield of EM was greater than that of LM. The first crop yields of barnyardgrass were affected by the preceding ryegrass varieties: greater yields of barnyardgrass were obtained when EM was the preceding crop than when LM was. The barnyardgrass sowing rate had no significant effect on either the first or the second crop yields. A sufficient number of seeds were produced to naturally establish a sward of barnyardgrass the following year in both the EM and LM plots. To verify the feasibility of this cropping system with ryegrass and barnyardgrass, we applied the system to a small field owned by a cattle farmer. The productivity cost of using this cropping system for grass production, excluding the cost depreciation for farm equipment, was comparable to the price of imported hay.

Improving the nutrient status of a commercial dairy farm: An integrated approach

AbstractMinimizing nutrient surpluses and improving efficiency of nutrient use are key challenges for all dairy farming production systems, driven by economic, environmental and increasing regulatory constraints. Our study examined the efficiency of N, P and K use on a commercial dairy farm through an integrated approach that evaluated the nutrient status of all aspects of the production system of the case-study farm, a 75 lactating Holstein cow dairy in Kings County, Nova Scotia, Canada. During the decade after 1988, the farm owner implemented a series of changes in production practices, including diversification of the crop rotation, implementation of a management intensive grazing (MIG) regime and adoption of a systematic approach to soil and nutrient management. Milk production, and associated farm exports of N, P and K, increased by 666 kg cow−1 between 1990 and 2000. Purchases of N-P-K fertilizers were eliminated in 1990 and feed nutrient imports were dramatically reduced. Feed costs per liter of milk declined from 14.3 cents (CDN) liter−1 in 1990–92 to 11.6 cents liter−1 in 1998–2000, even as feed prices increased regionally by 10–20% over the same period. Modeling of current whole farm mass N, P and K balance indicated that 25.0% of all N inputs are recovered inform products, milk and meat. Non-legume-derived field N input (67kg Nha−1 before losses) was close to optimum for the predominantly legume/grass-based forage cropping system. Model-determined annual farm nutrient surpluses (outputs-inputs) for P (9.0kgha−1 yr−1) and K (8.2 kg ha−1 yr−1) were significantly lower than those previously reported for regional confinement-based dairy farms, which were more reliant on corn production. However, data from 16 years of soil analysis (1985–2001) indicated an increase in soil-test P levels of approximately 2 mg kg−1 yr−1. Recent refinements in dairy animal dietary P levels have further reduced the farm P surplus (2.6 kg ha−1 in year 2001) and are shown as key to a strategy for reversal of the trend in soil-test P levels. In summary, the combined approach of whole-farm system nutrient management, crop diversification and MIG increased milk production and minimized costs while reducing farm nutrient inputs. The study demonstrates how an approach to dairy farm nutrient management which integrates livestock and crop nutrient requirements may reduce dairy farm nutrient loading while maintaining productivity.

Nitrogen mass balances in conventional, integrated and ecological cropping systems and the relationship between balance calculations and nitrogen runoff in an 8-year field experiment in Norway

For a cropping system to be sustainable, should not only the soil nitrogen (N) content be preserved but also the N runoff be minimised. Finding a simple but robust way to estimate N runoff would thus be a great advantage when evaluating cropping systems. In this study all major N flows in six different cropping systems, each covering 0.18 ha of a separately pipe drained field lysimeter, located in southeast Norway, were either measured or estimated over a period of 8-years. The effect of the cropping system on the soil N content was evaluated using mass balances of total N, and the usefulness of such N balances to predict N runoff (total N losses via drainage and surface water) was investigated. The experiment included systems with conventional arable cropping (CON-A), integrated arable-cropping (INT-A), ecological arable cropping (ECO-A), conventional forage cropping (CON-F), integrated forage cropping (INT-F), and ecological forage cropping (ECO-F). All the arable cropping systems resulted in a net reduction in the calculated soil N pool, and the reduction increased with decreasing N input. The only system, which did not alter the soil N content, was CON-F. The largest net reduction was estimated for ECO-A and ECO-F, which averaged 45 and 43 kg N ha −1 per year, respectively. The N runoff from the systems was in the range of 18–35 kg N ha −1 per year, with highest losses from the two conventional and lowest from the two ecological systems and INT-F. The forage systems had lower N runoff than the arable systems. The INT-F system appeared to be the most favourable system in terms of both soil N balance and N runoff. When the annual (May–April) N balance, calculated as N fertiliser+N slurry−N harvest, the annual precipitation and the precipitation from the previous year were used as predictors in a linear regression model, 87 and 65% of the variation in N runoff could be explained from the arable and forage cropping systems, respectively. The average N balance calculated for all years, on its own predicted 86% of the variation in N runoff from the arable systems. Mass N balances were thus found to be a useful tool for predicting N runoff, especially in systems with mainly arable crops.

Soil microbial biomass and mineralization of carbon and nitrogen in ecological, integrated and conventional forage and arable cropping systems

In a cropping systems experiment in southeastern Norway, ecological (ECO), integrated (INT) and conventional (CON) forage (FORAGE) and arable (ARABLE) model farms were compared. After 5 experimental years, topsoil was sampled in spring from spring grain plots and incubated for 449 days at controlled temperature (15 °C) and moisture content (50% water-holding capacity). There were no detectable differences between model farms in terms of total soil C or N. For INT and CON, however, values of microbial biomass C and N, microbial quotient (Cmic/Corg), and C and N mineralization were, or tended to be, higher for FORAGE than for ARABLE. For the ECO treatment, values were similar for FORAGE and ARABLE and did not differ significantly from that of CON-FORAGE. For INT and CON, the metabolic quotient (qCO2) was lower for FORAGE than for ARABLE. Again, for the ECO treatment, values were similar for FORAGE and ARABLE and did not differ significantly from that of CON-FORAGE. We estimated the sizes of conceptual soil organic matter pools by fitting a decomposition model to biomass and mineralization data. This resulted in a 48% larger estimate for CON-FORAGE than for CON-ARABLE of physically protected biomass C. For physically protected organic C the difference was 42%. Moreover, the stability of soil aggregates against artificial rainfall was substantially greater for CON-FORAGE than for CON-ARABLE. On this basis, we hypothesized that the lower qCO2 values in the FORAGE soils were mainly caused by a smaller proportion of active biomass due to enclosure of microorganisms within aggregates. Altogether, our results indicated a poorer inherent soil fertility in ARABLE than in FORAGE rotations, but the difference was small or absent in the ECO system, probably owing to the use of animal and green manures and reduced tillage intensity in the ECO-ARABLE rotation.

Allelopathy in Forage Crop Systems

AbstractSecondary plant metabolites and their degradation products are important in all agroecosystems including those with forage crops. Allelopathy affects cropping systems and interseeding of one species into established sods of another. Autotoxicity and heterotoxicity are types of allelopathy. Alfalfa (Medicago sativa L.) has been investigated as both an autotoxic and heterotoxic species. Reestablishment of alfalfa immediately after alfalfa has usually resulted in poor stands due to autotoxicity, and several other forage species also exhibit autotoxicity. Many forage species have shown heterotoxicity, both between forage species and weed species. Several investigators have identified various allelochemicals and/or families of allelochemicals as being responsible for allelopathic reactions. Identifying such chemicals would aid in developing resistant forage cultivars and in maintaining a productive and profitable crop. Crop rotation, cover‐crop management, interplanting, double cropping, no‐till planting, and nonrotational cropping systems are involved with allelopathic effects. Some alfalfa cultivars possess some resistance to these allelochemicals. Therefore, a breeding program could provide resistant germplasms. Various forage grasses and some weed species have demonstrated allelopathic effects on alfalfa, and alfalfa has allelopathic effects on some weed species. This alone may provide an insight for herbicide studies in alfalfa production.

Comparisons of Nitrogen Leaching in Ecological and Conventional Cropping Systems

ABSTRACT A cropping system project aimed at developing cropping systems which minimise nutrient leaching and maximise food quality and economy, was started at Apelsvoll Research Station in 1990. The experiment involves cash crop and forage crop systems with conventional and ecological farming. The systems are different with regard to crop rotation, nitrogen fertilization, soil tillage and plant protection. They are going to be improved by step-by-step changes. In the first experimental period, 1990/93, more than 80% of the nitrogen runoff was lost as nitrate in the drainage water. Averaged over all years and cropping systems the nitrate losses were 21.2 kg/ha. The nitrate runoff in the conventional cash crop system was more than twice as high as in the ecological cash crop system. For the forage crop systems the nitrate loss in the ecological system was reduced by 36% as compared to the conventional system. There was high variation in nitrate losses between the years. The most important factors influencing the nitrogen runoff in the different cropping systems seem to be crop rotation, soil tillage, time of manure application and amount of fertilizer.

Soil microbial biomass and in situ nitrogen mineralization after 20 years of different nitrogen fertilization and forage cropping systems

Soil microbial biomass and N mineralization were measured after 20 years of 12 treatments comprising all combinations of 3 cropping systems : annual forages (AF), rotation of temporary leys (TL), permanent grassland (PG) and 4 fertilization treatments : no N fertilization (C), mineral N (N), slurry (S), both (NS). After the cultivation period, the soils were ploughed and kept bare for leaching during three years. The microbial biomass was measured in three consecutive years in spring. The accumulated leached NO3-N gave an estimation of annual N mineralization. A significant effect of all treatments was found on N mineralization and biomass-C. Grassland duration and previous slurry application increased the two variables. Previous mineral N applications had no effect on N mineralization and decreased biomass-C. The relationship between N mineralization and microbial biomass-C was closer in the second and third year (r2 = 0.92 and 0.86 respectively ; n = 24) than in the first year (r2 = 0.63 ; n = 24), due to different behaviour of TL and PG treatments. In cropping systems including grasslands, a labile pool could operate together with microbial biomass to determine soil N mineralization.

Carbon dynamics and budgets in three upland double-cropping agro-ecosystems in Japan

Carbon dynamics and budgets were studied in three different double-cropping agro-ecosystems: upland rice-barley (R-B), peanut-wheat (P-W) and dentcorn-Italian ryegrass (C-I). The experiments were carried out in upland fields in Ibaraki Prefecture, central Japan, between June 1985 and May 1988. The annual amount of carbon fixed by the crops in the cropping systems was 617–627 g C m −2 for the food crop (R-B and P-W) systems and 1358 g C m −2 for the forage crop (C-I) systems. The amount of carbon supplied to the soil as organic matter was 338–382 g C m −2 for the food crop systems and 420 g C m −2 for the forage crop systems. However, the carbon respired by the heterotrophic respiration (respiration of soil fauna and micro-organisms) was 716–798 g C m −2 and 1050 g C m −2 in the respective systems. Therefore, the annual carbon balance was estimated to be −400 g C m −2 for the food crop systems and −600 g C m −2 for the forage crop systems. These results suggest that effective agronomic measures are needed to maintain the carbon balance in prevailing agricultural ecosystems in order to sustain soil fertility, and that the upland agro-ecosystems may contribute to the increase in the carbon dioxide concentration of the atmosphere as the carbon accumulated in the soil is constantly being released into the atmosphere.

Comparison of Forage Cropping Systems in the Oxisol of Kerala

An experiment conducted to campare the productivity of a few forage cropping systems and to study the feasibility of mixing cowpea with annual cereals and perennial grasses, in the laterite soils of Kerala revealed that among the grasses, hybrid napier was superior in terms of forage and crude protein yields followed by guinea grass. Mixing cowpea with perennial grasses (hybrid napler and guinea grass) does not appear to be compatible at the normal spacing of the grassos, Cowpea mixes well with the annual cereals (maize and sorghum) but the yields of these crops and crop combinations are comparatively low.