Two field experiments were carried out at Sanhout village Menia Al-Kamh district-Sharkia province under Agronomy Department supervision, Faculty of Agriculture, Zagazig University, Egypt, during two summer successive growing seasons i.e. 2009 and 2010.The investigation aimed to study the effect of farmyard manure (FYM) (Without, 20 and 40 m3 /fed.) and nitrogen fertilizer levels (Without, 45 ,90 and 135 kg N / fed.) on yield and land use efficiency of maize (Zea mays L.)soybean (Glaycine max (L.) Merr.) intercropped. Soybean variety Giza-22 was sown at 93.333 plant per fed. as pure stand and intercropping as well and maize variety TWC 324 which was sown at 23,333 plant per fed. as pure stand and intercropping (3:3) were used in this investigation included: Pure stand of maize variety TWC 324 (23,333 plant per fed.), Pure stand of soybean variety Giza-22 (93.333 plant per fed.), maize was sowing on one side and two plants per hill (46.666 plant per fed) instead of one plant per hill in the solid plots, simultaneously, soybean was always sown and thinned as two plants in hill 10 cm apart on both sides of the ridge (186.666 plant / fed) instead of one side of the ridge in the solid plots (growing three ridges of maize in alternation with three ridges of soybean). The obtained results showed that: Grain and seed yields of maize and soybean components significantly reduced by intercropping ,compared to the pure stand yield, However, the relative yield of those two components was 82 and 85% for maize and soybean ,respectively. Thus, intercropping efficiency i.e. economic yield advantage of the combined intercrop yield reached 67% in the maizesoybean intercrop. Grain and seed yields of maize and soybean components were significantly increased due to FYM application up to 40 m3 and N up to 135 kg N / fed.Further more, land equivalent ratio (LER), area time equivalent ratio (ATER) and its LER average , land equivalent coefficient (LEC) and Agressivity (A) criterions were observed that addition of FYM did not have any significant effect on aforementioned traits in both seasons and their combined analysis. But, adding N fertilizer have significant effect on those traits (combined analysis). However, intercropping of maize and soybean, again, was more productive than growing them separately, as can be observed from the LER, ATER and its average values which were greater than unity and from the LEC values which were greater than 0.25 and from sign of agressivity values which were positive for soybean component and negative for maize at three FYM and four N fertilizer levels.

The aim of this study was to investigate the response of two yellow maize hybrids (Single Cross 176 and Three-way Cross 352) to three plant densities (20000, 24000 and 30000 plants/fad.), and nitrogen-farmyard combination fertilizer levels (60, 80 and100 kg N/fad., without addition of farmyard manure (FYM) and 60 kg N/fad.+20 m 3 FYM/fad., 80 kg N/fad.+ 20 m 3 FYM/fad., and 100 kg N/fad.+20 m 3 FYM/ fad.) under clay soils conditions. The obtained results could be summarized as follows: The tried three maize plant densities had different effects on plant height (cm), ear diameter and length (cm), number of rows/ear, number of kernels/row, 100-kernel weight, kernel weight/ear, and biological yield (ton/fad.) during both seasons and their combined analysis, but the differences among the tried three maize plant densities on aforementioned traits did not reach the level of significance. Results of the first season and the combined analysis detected significant differences among the tried plant densities on ear yield/fad. Where, ear yield/fad., and grain yield/fad., in the first season and combined analysis, harvest index and grain: stover ratio in the two seasons and their combined analysis were significantly increased due to increasing maize density from 20000 or 24000 and up to 30000 plants/fad. Maize SC 173 cultivar appeared to produced taller plants, longer ears and larger number of kernels/row than TWC 352 cultivar. The later produced larger ear diameter, number of rows/ear, 100-kernel weight, kernel weight/ear, ear yield/fad., grain and biological yields/fad., than SC 173 one. No significant differences between two maize cultivars regarding harvest index and grain: stover ratio was observed. The first and the second increments in nitrogen levels up to 100 kg N/fad., with or without addition of farmyard manure was accompanied by a significant increase in ear diameter (cm), ear length (cm), number of rows/ear, number of kernels/row, 100-kernel weight (g), kernel weight/ear (g), ear yield/fad., grain and biological yields (ton/fad.) but harvest index and grain: stover ratio were reduced during both seasons and their combined analysis. These results finally recommend sowing maize cultivar TWC 352 with dense planting of 30000 plants/fad., and raising nitrogen level up to 80 kg N/fad., with addition of farmyard manure to maximize grain yield/fad., under the experimental site and other likely environmental condition.