Broadbalk Description of other crop yield data
Other arable crops have been included in the rotational sections of Broadbalk since 1968 (see Cropping plan for details). Yield data is available from the following datasets:
BKBEANS Spring bean grain and straw yields 1968 -1978
BKPOTATO Potato tuber yields 1968 -1996
BKOATS Winter oat grain and straw yields 1996 - current year
BKMAIZE Forage maize whole crop yields 1997 - 2017
Spring field beans (Vicia faba) were grown on the rotational sections of Broadbalk between 1968 and 1978, as part of the potato > beans > wheat rotation on sections 2, 4 and 7. For full details of the cropping sequence see Cropping on Broadbalk. The varieties were Maris Bead (1968-74), Minor (1975) and Minden (1976-78). The beans were sown in March and generally harvested in September. The crops received the same inorganic fertilizer (including N) and FYM applications as the wheat crops. Grain and straw yields at 85% DM and thousand grain weights are available. Sowing and harvest dates are available from the e-RA Curators.
Potato (Solanum tuberosum) was grown on the rotational sections of Broadbalk between 1968 and 1996, as part of the potato > beans > wheat rotation of Sections 2, 4 and 7 (1968-78) and then as part of the potato > wheat > wheat > wheat > fallow rotation of Sections 2-5 and 7 (1979-96). For full details of the cropping sequence see Cropping on Broadbalk. The varieties grown were Majestic (1968-69), King Edward (1970-75), Pentland Crown (1976-93), Estima (1994-96). The crops received the same inorganic fertilizer and FYM applications as the wheat crops. Chitted potato seed was generally planted in April and harvested in September; please apply to the e-RA Curators for a full list of dates since 1968. The potatoes were usually harvested earlier than normal to allow timely drilling of winter wheat, hence the yields are lower than might be expected.
Data available includes total tuber yield, tuber DM content and % ware (tubers that do not pass through a 3.81cm ‘riddle’ or grader). ‘Ware’ potatoes are those grown for human consumption, which need to be a minimum size, generally over 40mm. Potatoes are graded according to size, using a potato riddler.
Winter oats (Avena sativa) has been grown on the rotational sections 2-5 and 7 since 1996, as part of the wheat > wheat > wheat > oats > maize rotation. For full details of the cropping sequence see Cropping on Broadbalk. The varieties grown were Image (1996-2000), Revisor (2001) and Gerald (2002-onwards). Revisor, a spring variety, was sown in 2001 due to poor autumn weather preventing a winter variety from being sown. Oats are generally sown in October and harvested in August; please apply to the e-RA Curators for a full list of dates since 1996. No fertilizer N or FYM is applied to the oats crops, though K and Mg are applied as usual. Thus, on plots were P and K is not limiting, any differences in yield between treatments are due to residues of inorganic N from previous applications or from differing amounts of N being mineralised from the soil organic matter.
Forage maize (Zea mays) is grown as a whole crop, for silage. It has been grown in the rotational sections 2-5 and 7 since 1997, as part of the wheat > wheat > wheat > oats > maize rotation. Maize is a C4 plant. As such, the carbon it contains has a different 13C "signature" than that in the C3 plants that have been grown previously on Broadbalk. Thus, we can distinguish maize-derived organic matter from that of organic matter already in the soil. For full details of the cropping sequence see Cropping on Broadbalk. The variety Hudson has been grown since 1997. Forage maize is generally sown in May and harvested in September; please apply to the e-RA Curators for a full list of dates since 1997. Maize receives the usual inorganic fertilizer and FYM applications, the same as wheat. In 2013, forage maize yields may have been reduced, due to the accidental application of herbicide to the crop in June/July 2013. The last crop of forage maize was grown in 2017. A new rotation including winter beans instead of maize was started in 2018.
Further details can be obtained from the e-RA Curators
For more information, refer to the Rothamsted Guide to the Classical Experiments 2006