Effect of lupins and wheat on the yield of subsequent wheat crops grown at several rates of applied nitrogen

Abstract

The responses of wheat to various rates of application of nitrogen fertiliser were compared following lupins (WL) or wheat (WW) in the previous year. Results covered 10 sites and trials were carried out between 1979 and 1984. giving 26 site-year comparisons. The trials were on sandy or duplex (sand over clay) soils. The overall yield of WL was greater than WW on 21 occasions (significant in 10 cases, P < 0.05), less than WW on 2 occasions (both significantly) and there was no difference on 3 occasions. When no nitrogen was applied the advantage of WL was 41% (WL 1.20 t/ha and WW 0.85 t/ha). The response to nitrogen differed between trials; over all trials a quadratic model best described the responses. There were significant interactions between rotation and nitrogen rate in 10 comparisons. In 4 of these cases, response to nitrogen with WW was greater than with WL and these response curves approached I another but did not meet, indicating that both residual nitrogen from the lupins and some other benefit from the lupins were involved. In 5 cases the greater response on WW resulted in convergence with the WL response curve, suggesting that residual nitrogen explained all of the benefit of lupins. In these cases the amount ofnitrogen fertiliser required to bring the yield of WW to that of the WL without nitrogen ranged from 20 to 47 kg N/ha, with a mean of 37 kg N/ha. Parallel response curves were observed In 12 cases, indicating involvement of factors other than residual nitrogen in the response to lupins, e.g. disease cleaning effects or slow release of nitrogen throughout the season. The type of response could not be related to particular site characteristics. When quadratic coefficients were averaged to give 'average response curves', similar rates of applied nitrogen were required for maximum yields in both WW and WL, and the maximum yields were 1.23 t/ha for WW and 1.41 t/ha for WL. The average advantage of WL over WW, in the absence of nitrogen fertiliser. was 350 kg/ha.

Nitrogen mineralization, nitrate leaching and crop growth after ploughing-in leguminous and non-leguminous grain crop residues

“…Nevertheless, in this experiment yields of the spring wheat test crop were generally greater following leguminous crops, with the size of the yield increase relative to non-leguminous crops (0-5-10 t/ha) similar to that reported in other studies (Reeves et al 1984;Evans 1987;Rowland et al 1988). Similar trends were apparent for the N grain yield and N total yield of the spring wheat crop.…”

“…i M T B n n n r T i r i N mineral N and reduced incidence of crop disease i M i R U U U t i i u i N following the grain legumes (Reeves et al 1984; A mixed cropping (pasture/arable) system of farming Jessop & Mahoney 1985;Rowland et al 1988). is commonly practised on over 750000 ha of land on Thus, in the typical, short-term arable rotations the Canterbury Plains of New Zealand (Haynes & in Canterbury where soil disease problems are Francis 1990).…”

Field measurement of lupin belowground nitrogen accumulation and recovery in the subsequent cereal-soil system in a semi-arid Mediterranean-type climate

“…They offer a pest and disease break, improve soil structure and input N to the system via biological nitrogen (N) fixation (Siddique and Sykes 1997), although in recent years economic and agronomic constraints have contributed to a decrease in area sown (Evans et al 2003). The narrow-leaved lupin (Lupinus angustifolius) has been a particular success on coarse textured neutral to acid sands across the wheat growing regions of Australia, directly providing economic gains via high grain yields but also indirectly increasing the grain yield and protein of subsequent cereal crops (Evans et al 1991(Evans et al , 2001Heenan et al 1998;Rowland et al 1988). Knowledge of the potential amount of N available from grain legume residues for uptake by a following cereal crop is important, particularly when assessing fertiliser N requirements of low input rain-fed farming systems.…”

Influence of agronomic management of legume crops on soil accumulation with nitrate

“…Legume crops are valuable in cereal cropping systems because they increase soil concentration of plant available N (Jones 1974;Reeves et al 1984;Strong et al 1986;Evans et al , 1991Rowland et al 1988;Campbell et al 1992), from processes occurring during the growth of a legume crop and after it is harvested. In the pre-harvest phase, Evans et al (1985Evans et al ( , 1989 and Evans and Taylor (1987) predicted that nitrate derived from pre-existing soil N may accumulate under legume crops, relative to cereals: nitrate they termed 'spared N' or 'conserved N'.…”