samples/texts/1169714/page_5.md

Table 2. Different parameters of the fitted model of semivariogram.

S.No	Depth (cm)	Type of Model	Range	Nugget	Sill	Nugget as % of Sill	Spatial Dependence
First Observation
1	7.5	Spherical	125	0.45	3.05	14.75	Strongly dependent
2	15	Spherical	113.1	0.327	2.947	11.09	Strongly dependent
3	30	Spherical	110	0.46	3.1	14.84	Strongly dependent
4	45	Spherical	113.09	0.638	5.748	11.09	Strongly dependent
5	60	Spherical	113.09	1.1787	10.61	11.10	Strongly dependent
Second Observation
1	7.5	Spherical	125	2.1	14	15	Strongly dependent
2	15	Spherical	113.09	0.548	4.94	11.09	Strongly dependent
3	30	Spherical	113.09	0.836	7.525	11.10	Strongly dependent
4	45	Spherical	113.09	0.848	7.634	11.10	Strongly dependent
5	60	Spherical	113.09	0.804	7.244	11.09	Strongly dependent

the field, soil moisture is almost constant Figure 6(a), which is due to the bare field, which provides a free evaporation surface.

As shown in Figure 7(a) for 15 cm depth, variability is large as compared to 7.5 cm depth, but the same pattern is observed at this depth, i.e., maximum in the corners and minimum at the centre. Mean moisture content at 15 cm depth is higher than 7.5 cm depth.

As shown in Figures 8(a), Figure 9(a) and Figure 10 (a) shows a uniform spatial variability with 30 cm depth, 45 cm depth and 60 cm depth respectively. Mean moisture content was found higher at 60 cm depth than other depths.

In the second set of observations, it was observed that for 7.5 cm depth, moisture content at the corner of the fields is almost constant whereas in the middle it is very high which shows non uniform supply of water as shown in Figure 6(c).

For 15 cm depth, high spatial variability is obtained as compared to 7.5 cm depth Figure 6(c). In the middle, the moisture content is very high at 7.5 cm depth due to the same reason of non uniform supply of water as shown in Figure 7(c).

For 30 cm depth, 45 cm depth and 60 cm depth the variability is almost same Figure 8(c), 9(c) and 10(c), respectively.

From the maps, it was observed that in the first set of observation high spatial variability was observed as compared to the second set of observation. This is because of the reason that the second sets of observation were taken after irrigation. Soil profile is almost saturated with water. Some variability was observed, which shows the non uniform supply of irrigation water. The maximum variability is observed up to 30 cm depth where as for 45 cm and 60 cm depths, variability is almost constant in both sets of observations. In both sets of observations maximum spatial variability was observed at 30 cm depth (Figures 8(a) and 8(c)).

Figure 1. (a) Experimental semivariogram of first observation at 7.5 cm depth and fitted model; (b) Experimental semivariogram of second observation at 7.5 cm depth and fitted model.