ca20                  package:geoR                  R Documentation

_C_a_l_c_i_u_m _c_o_n_t_e_n_t _i_n _s_o_i_l _s_a_m_p_l_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     This data set contains the calcium content measured in soil
     samples taken from the 0-20cm layer at 178 locations within a
     certain study area divided in three sub-areas. The elevation at
     each location was also recorded.

     The first region is tipically flooded during the rain season and
     not used as an experimental area. The calcium levels would
     represent the natural content in the region. The second region has
     received fertilizers a while ago and is tipically occupied by rice
     fields. The third region has recieved fertilizers recently and is
     frequently used as an experimental area.

_U_s_a_g_e:

     data(ca20)

_F_o_r_m_a_t:

     The object 'ca20' belongs to the class 'geodata' and is a list
     with the following elements:

     '_c_o_o_r_d_s' a matrix with the coordinates of the soil samples.  

     '_d_a_t_a' calcium content measured in mmol_c/dm^3.  

     '_c_o_v_a_r_i_a_t_e' a data-frame with the covariates

          '_a_l_t_i_t_u_d_e' a vector with the elevation of each sampling
               location, in meters (m).

          '_a_r_e_a' a factor indicating the sub area to which the
               locations belongs.


     '_b_o_r_d_e_r_s' a matrix with the coordinates defining the borders of
          the area.  

     '_r_e_g_1' a matrix with the coordinates of the limits of the sub-area
          1. 

     '_r_e_g_1' a matrix with the coordinates of the limits of the sub-area
          2. 

     '_r_e_g_1' a matrix with the coordinates of the limits of the sub-area
          3. 

_S_o_u_r_c_e:

     The data was collected by researchers from PESAGRO and
     EMBRAPA-Solos, Rio de Janeiro, Brasil and provided by Dra. Maria
     Cristina Neves de Oliveira.

     Capeche, C.L. _et al._ (1997) Caracterizao pedolgica da fazenda
     Angra - PESAGRO/RIO - Estao experimental de Campos (RJ). CD-ROM
     In: _Congresso BRASILEIRO de Cincia do Solo_ 26, Informao,
     globalizao, uso do solo; Rio de Janeiro, 1997. trabalhos. Rio de
     Janeiro: Embrapa/SBCS, 1997.

_R_e_f_e_r_e_n_c_e_s:

     Further information on the package 'geoR' can be found at:
      <URL: http://www.est.ufpr.br/geoR>.

