Legumes in catch crop mixtures: Effects on nitrogen retention and availability, and leaching losses

Abstract. Improving N cycling in agroecosystems is one of the key challenges in reducing the environmental footprint of agriculture. Further, uncertainty in precipitation makes crop water management relevant in regions where it has not been necessary thus far. Here, we focus on the potential of winter-killed catch crops to reduce N leaching losses from N mineralization over the winter and soil water management. We compared four single catch crops (white mustard, phacelia, Egyptian clover and bristle oat) and a fallow treatment with two catch crop mixtures with 4 and 12 plant species (Mix4 and Mix12). High-resolution soil mineral N (Nmin) monitoring in combination with modelling of spatiotemporal dynamics served to assess N cycling under winter-killed catch crops, while soil water was continuously monitored in the rooting zone. Catch crops depleted the residual Nmin pools by between 40 and 72 % compared to the fallow. The amount of residual N uptake was lowest for clover and not significantly different among the other catch crops. Catch crops that produce high N litter materials, such as clover and mustard leaves, showed an early N mineralization flush immediately after their termination and the highest leaching losses from litter mineralization over the winter. Except for clover, all catch crops showed Nmin values between 18 and 92 % higher on the sowing date of the following maize crop. However, only Mix12 was statistically significant. Catch crops depleted the soil water storage in the rooting zone during their growth in autumn and early winter, but preserved water later on when their residues cover the ground. The shallow incorporation of catch crop residues increased water storage capacity during the cropping season of the main crop even under drought conditions. Hence, catch cropping is not just a simple plant cover during the winter but improved the growth conditions for the following crop at decreased N losses. Mixtures have been shown to compensate for the weaknesses of individual catch crop species in terms of nutrient capture, mineralization and transfer to the following main crop as well as for soil water management. Detailed knowledge about plant performance during growth and litter mineralization patterns is necessary to make optimal use of their full potential.

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Very Low Nitrogen Leaching in Grazed Ley-Arable-Systems in Northwest Europe

Agronomy ◽

10.3390/agronomy11112155 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2155

Author(s):

Hendrik P. J. Smit ◽

Thorsten Reinsch ◽

Christof Kluß ◽

Ralf Loges ◽

Friedhelm Taube

Keyword(s):

Nitrate Leaching ◽

C Sequestration ◽

Winter Precipitation ◽

Catch Crop ◽

Pasture Management ◽

N Losses ◽

Leaching Losses ◽

Soil C ◽

Permanent Grassland ◽

Northwest Europe

High input dairy farms that are located on sandy soils in northwest Europe are predisposed to substantial nitrate leaching during a surplus of winter precipitation. Leys within integrated crop-livestock systems play an important role in soil fertility, soil C sequestration and soil N mineralization potentials. Therefore, leys are a feasible option that can be utilized to reduce local N losses to the environment, especially following maize grown for silage. We hypothesize that grass-clover leys ensure low nitrate leaching losses even when grazed intensively. The extent to which NO3-leaching occurred across seven different pasture management systems in terms of their sward composition, cutting, grazing, fertilization and combinations thereof was investigated in integrated animal-crop grazing systems over three winter periods (2017/2018, 2018/2019 and 2019/2020). The observed grazed systems were comprised of cut-used- and grazed grass-clover swards (0, 1 and 2 years after establishment following cereals), a catch crop grazed late in the year as well as a cut-used permanent grassland for comparison. Overall, all treatments resulted in nitrate leaching losses that did not exceed the WHO-threshold (25 mg nitrate/L). The highest level of NO3-leaching was observed in the catch crop system and the lowest in cut-used permanent grassland, with NO3-N losses of 19.6 ± 5.3 and 2.1 ± 0.3 kg NO3-N ha−1 year−1. Annual herbage yields were in the range of 0.9 to 12.4 t DM ha−1 and nitrogen yields varied between 181 ± 51 and 228 ± 66 kg N ha−1 during the study period. The highest herbage-N-yields were observed from the 1- and 2-year-old grass-clover leys. The highest N-field-balance was observed for the grazed leys and the lowest for the cut-used permanent grassland. However, no correlation was found between the highly positive field-N-balance and the amount of NO3-leached. This indicates a high N carry-over from grass-clover swards to the subsequent cash crop unit instead of increasing the risk of groundwater contamination from grazed leys in integrated animal crop-systems and underlines the eco-efficiency of dairy farming based on grazed ley systems.

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Sweet corn significantly increases nitrogen retention and reduces nitrogen leaching as summer catch crop in protected vegetable production systems

Soil and Tillage Research ◽

10.1016/j.still.2018.03.003 ◽

2018 ◽

Vol 180 ◽

pp. 148-153 ◽

Cited By ~ 9

Author(s):

Ruiying Guo ◽

Wei Qin ◽

Chunguang Jiang ◽

Lingyun Kang ◽

Claas Nendel ◽

...

Keyword(s):

Sweet Corn ◽

Production Systems ◽

Nitrogen Retention ◽

Nitrogen Leaching ◽

Vegetable Production ◽

Catch Crop ◽

Summer Catch Crop

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The benefit of leafy vegetable as catch crop to mitigate N and P leaching losses in intensive plastic-shed production system

Journal of Soils and Sediments ◽

10.1007/s11368-021-02930-1 ◽

2021 ◽

Author(s):

Hongdong Xiao ◽

Xin Fan ◽

Haijun Sun ◽

Min Yu ◽

Weiming Shi ◽

...

Keyword(s):

Production System ◽

Leafy Vegetable ◽

Catch Crop ◽

Leaching Losses ◽

P Leaching

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Kinetic parameters of nitrate uptake by different catch crop species: effects of low temperatures or previous nitrate starvation

Physiologia Plantarum ◽

10.1034/j.1399-3054.1993.880112.x ◽

1993 ◽

Vol 88 (1) ◽

pp. 85-92 ◽

Cited By ~ 1

Author(s):

P Laine ◽

A. Ourry ◽

J. Macduff ◽

J. Boucaud ◽

J. Salette

Keyword(s):

Kinetic Parameters ◽

Low Temperatures ◽

Nitrate Uptake ◽

Catch Crop ◽

Crop Species ◽

Species Effects ◽

Nitrate Starvation

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An evaluation of a strategic de-stocking regime for dairying to improve nitrogen efficiency and reduce nitrate leaching from dairy farms in nitrate-sensitive areas

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2000.62.2401 ◽

2000 ◽

pp. 105-110

Author(s):

Cecile De Klein ◽

Jim Paton ◽

Stewart Ledgard

Keyword(s):

New Zealand ◽

Nitrate Leaching ◽

Management Practice ◽

Field Measurements ◽

Dairy Farms ◽

Nitrogen Efficiency ◽

Management Tool ◽

Pasture Production ◽

Leaching Losses ◽

Sensitive Areas

Strategic de-stocking in winter is a common management practice on dairy farms in Southland, New Zealand, to protect the soil against pugging damage. This paper examines whether this practice can also be used to reduce nitrate leaching losses. Model analyses and field measurements were used to estimate nitrate leaching losses and pasture production under two strategic de-stocking regimes: 3 months off-farm or 5 months on a feed pad with effluent collected and applied back to the land. The model analyses, based on the results of a long-term farmlet study under conventional grazing and on information for an average New Zealand farm, suggested that the 3- or 5-month de-stocking could reduce nitrate leaching losses by about 20% or 35-50%, respectively compared to a conventional grazing system. Field measurements on the Taieri Plain in Otago support these findings, although the results to date are confounded by drought conditions during the 1998 and 1999 seasons. The average nitrate concentration of the drainage water of a 5-month strategic de-stocking treatment was about 60% lower than under conventional grazing. Pasture production of the 5-month strategic de-stocking regime with effluent return was estimated based on data for apparent N efficiency of excreta patches versus uniformlyspread farm dairy effluent N. The results suggested that a strategic de-stocking regime could increase pasture production by about 2 to 8%. A cost/ benefit analysis of the 5-month de-stocking system using a feed pad, comparing additional capital and operational costs with additional income from a 5% increase in DM production, show a positive return on capital for an average New Zealand dairy farm. This suggests that a strategic destocking system has good potential as a management tool to reduce nitrate leaching losses in nitrate sensitive areas whilst being economically viable, particularly on farms where an effluent application system or a feed pad are already in place. Keywords: dairying, feed pads, nitrate leaching, nitrogen efficiency, productivity, strategic de-stocking

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